Composition for forming resist underlayer film and patterning process using the same

ABSTRACT

The invention provides a composition for forming a silicon-containing resist underlayer film comprising: (A) a silicon-containing compound obtained by a hydrolysis-condensation reaction of a mixture containing, at least, one or more hydrolysable silicon compound shown by the following general formula (1) and one or more hydrolysable compound shown by the following general formula (2), and (B) a silicon-containing compound obtained by a hydrolysis-condensation reaction of a mixture containing, at least, one or more hydrolysable silicon compound shown by the following general formula (3) and one or more hydrolysable silicon compound shown by the following general formula (4). There can be provided a composition for forming a resist underlayer film applicable not only to a resist pattern obtained in a negative development but also to a resist pattern obtained in a conventional positive development, and a patterning process using this composition
 
R 1   m1 R 2   m2 R 3   m3 Si(OR) (4-m1-m2-m3)   (1)
 
U(OR 4 ) m4 (OR 5 ) m5   (2)
 
R 6   m6 R 7   m7 R 8   m8 Si(OR 9 ) (4-m6-m7-m8)   (3)
 
Si(OR 10 ) 4   (4).

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a composition for forming asilicon-containing resist underlayer film and a patterning process usingthe same.

2. Description of the Related Art

In 1980s, a g-line (436 nm) or an i-line (365 nm) of a mercury lamp wasused as an exposure light to be used in a resist pattern forming. As amean for further miniaturization, a method of shifting to a shorterwavelength of an exposing light was assumed to be effective. As aresult, in a mass production process after DRAM (Dynamic Random AccessMemory) with 64-megabits (0.25 μm or less of a processing dimension) in1990s, a KrF excimer laser (248 nm), a shorter wavelength than an i-line(365 nm), was used in place of an i-line as an exposure light source.However, in production of DRAM with an integration of 256 M, 1 G andhigher which require further miniaturized process technologies (processdimension of 0.2 μm or less), a light source with a further shortwavelength is required, and thus a photo lithography using an ArFexcimer laser (193 nm) has been investigated seriously since about adecade ago. At first, an ArF lithography was planned to be applied to adevice starting from a 180 nm node device, but a KrF excimer laserlithography lived long to a mass production of a 130 nm node device, andthus a full-fledged application of an ArF lithography will start from a90 nm node. Further, a study of a 65 nm node device by combining with alens having an increased NA till 0.9 is now underway.

Further shortening of wavelength of an exposure light is progressingtowards the next 45 nm node device, and for that an F₂ lithography witha 157 nm wavelength became a candidate. However, there are many problemsin an F₂ lithography; an increase in cost of a scanner due to the use ofa large quantity of expensive CaF₂ single crystals for a projector lens,extremely poor sustainability of a soft pellicle, which leads to achange of an optical system due to introduction of a hard pellicle, adecrease in an etching resistance of a resist film, and the like.Because of these problems, it has been abandon the development of an F₂lithography and introduced an ArF immersion lithography earlier.

In the ArF liquid immersion lithography, water having a refractive indexof 1.44 is inserted between the projection lens and a wafer by a partialfilling manner to enable high-speed scanning, thereby allowing toconduct mass-production of 45 nm node devices by a lens having an NA onthe order of 1.3.

Exemplary candidates of lithography techniques for 32 nm nodes includeextreme ultraviolet (EUV) lithography at a wavelength of 13.5 nm. Then,exemplary objects accompanying to the EUV lithography are to increase anoutput of laser, enhance a sensitivity of resist film, enhance aresolution, decrease a line edge roughness (LER), achieve a defect-freeMoSi laminate mask, lower aberrations of a reflecting mirror, forexample, thereby leaving a pile of objects to be attained.

Another candidate of 32 nm nodes is a high refractive index liquidimmersion lithography, the development of which has been abandoned, dueto lower transmittance of LuAG as a candidate of high refractive indexlens therefor, and due to failure of achievement of a refractive indexof a liquid to be increased up to a targeted value of 1.8.

As mentioned above, a photo-exposure method used as a general-purposetechnology is reaching an inherent limit of its resolution due towavelength of a light source. Accordingly, in recent years, an organicsolvent development, with which a very fine hole pattern that cannot beaccomplished by a conventional patterning process with a positive toneusing an alkaline developer is obtained by a patterning process with anegative tone using an organic solvent developer, has been receiving anattention again. This is a process to form a negative pattern by anorganic solvent developer by using a high resolution positive resistcomposition. In addition, investigation is being carried out to obtaintwofold resolution by combining two developments of an alkalinedevelopment and an organic solvent development.

Usable as an ArF resist composition for development in a negative toneby an organic solvent like this, is a positive ArF resist composition ofa conventional type, and examples of patterning processes therefor areshown in Japanese Patent Laid-Open (kokai) No. 2008-281974, JapanesePatent Laid-Open (kokai) No. 2008-281980, Japanese Patent Laid-Open(kokai) No. 2009-53657, for example.

As one method to transfer the thus formed negative-tone pattern to asubstrate, multi-layer resist process have been used. The methods areconfigured to: interpose an intermediate film, for example a resistunderlayer film containing silicon atom, having an etching selectivitydifferent from that of a photoresist film, i.e., a resist upper layerfilm, between the resist upper layer film and a body to be processed;obtain a pattern in the resist upper layer film; thereafter transfer thepattern to the resist underlayer film by dry etching by using theobtained resist upper layer film pattern as a dry etching mask; andfurther transfer the pattern onto the body to be processed by dryetching by using the obtained pattern of the resist underlayer film as adry etching mask.

Examples of silicon-containing resist underlayer films to be used in theabove-described multi-layer resist process include silicon-containinginorganic films by CVD, such as SiO₂ films (Japanese Patent Laid-Open(kokai) No. H7-183194, for example) and SiON films (Japanese PatentLaid-Open (kokai) No. H7-181688, for example); and films obtained byspin coating, such as SOG (spin-on-glass) films (Japanese PatentLaid-Open (kokai) No. 2007-302873, for example), and crosslinkablesilsesquioxane films (Japanese translation of PCT internationalapplication No. 2005-520354, for example).

SUMMARY OF THE INVENTION

Contrary to a positive development (alkaline development) in which aresist pattern formed of a hydrophobic compound not soluble in analkaline developer is obtained, in a negative development (organicsolvent development), a resist pattern formed of a hydrophilic organiccompound containing, in high concentration, an acidic group such as acarboxyl group generated by a deprotection reaction is obtained; andthus, performance of a photo resist cannot be realized sufficiently witha conventional resist underlayer film for an alkaline development.

On the other hand, if a resist underlayer film used in a negativedevelopment is different from a resist underlayer film used in apositive development, piping equipment solely dedicated to respectivedevelopments are necessary; and thus, this is economically irrational.

The present invention was made in view of the problems as mentionedabove, and has an object to provide (i) a composition for forming asilicon-containing resist underlayer film applicable not only to aresist pattern formed of a hydrophilic organic compound obtained in anegative development but also to a resist pattern formed of ahydrophobic compound obtained in a conventional positive development,and (ii) a patterning process using this composition.

Namely, the present invention provides a composition for forming asilicon-containing resist underlayer film comprising;

(A) a silicon-containing compound obtained by a hydrolysis-condensationreaction of a mixture containing, at least, one or more hydrolysablesilicon compound shown by the following general formula (1) and one ormore hydrolysable compound shown by the following general formula (2),R¹ _(m1)R² _(m2)R³ _(m3)Si(OR)_((4-m1-m2-m3))  (1)

wherein, R represents a hydrocarbon group having 1 to 6 carbon atoms; atleast one of R¹, R², and R³ is an organic group containing a hydroxylgroup or a carboxyl group, the groups being substituted with anacid-labile group, while the other is a hydrogen atom or a monovalentorganic group having 1 to 30 carbon atoms; and m1, m2, and m3 represent0 or 1 and satisfy 1≦m1+m2+m3≦3;U(OR⁴)_(m4)(OR⁵)_(m5)  (2)

wherein, R⁴ and R⁵ represent an organic group having 1 to 30 carbonatoms, and m4+m5 is the same number as the number determined by valencyof U; m4 and m5 represent an integer of 0 or more; and the U is anelement belonging to groups of III, IV, or V in a periodic table exceptfor carbon and silicon;

(B) a silicon-containing compound obtained by a hydrolysis-condensationreaction of a mixture containing, at least, one or more hydrolysablesilicon compound shown by the following general formula (3) and one ormore hydrolysable silicon compound shown by the following generalformula (4),R⁶ _(m6)R⁷ _(m7)R⁸ _(m8)Si(OR⁹)_((4-m6-m7-m8))  (3)

wherein, R⁹ represents an alkyl group having 1 to 6 carbon atoms, andeach R⁶, R⁷, and R⁹ represents a hydrogen atom or a monovalent organicgroup having 1 to 30 carbon atoms; and m6, m7, and m8 represent 0 or 1and satisfy 1≦m6+m7+m3≦8; andSi(OR¹⁰)₄  (4)

wherein, R¹⁰ represents an alkyl group having 1 to 6 carbon atoms.

In a positive development, it has been experimentally known that, if acontact angle of a resist pattern obtained after photo-exposure is madecoincident with a contact angle of a resist underlayer film, it iseffective to enhance adhesion and to lower roughness in a resistpattern. However, in a negative pattern obtained by a negativedevelopment, when comparison is made on film properties between thephotoresist film before photo-exposure and the resist pattern afterphoto-exposure, amount of a hydrophilic group such as a carboxyl groupand a phenolic hydroxyl group due to elimination of an acid-labile groupcaused by an acid generated by the photo-exposure is increased in theresist pattern after the photo-exposure; and as a result, a contactangle of the resist pattern is shifted toward a hydrophilic side, i.e.,a lower side, as compared with that before the photo-exposure. Becauseof this, it was found, in a conventional underlayer film for positiveresist whose contact angle is made coincident with that of a photoresistfilm before the photo-exposure, discrepancy from the contact angle ofthe negative pattern is generated thereby causing pattern fall and anadverse effect in roughness. In other words, if the contact angle in apart of the resist underlayer film corresponding to an exposed area ofthe photoresist film is approximated to the contact angle of thenegative pattern of the photoresist and the contact angle in the partcorresponding to an unexposed area thereof is approximated to thecontact angle of the positive pattern of the photoresist, a resistunderlayer film applicable to both the negative and positive developmentprocesses can be obtained. Accordingly, the composition for forming asilicon-containing resist underlayer film as mentioned above becomes acomposition for forming a silicon-containing resist underlayer filmgiving a silicon-containing resist underlayer film that has an enhancedadhesion with a photoresist pattern and does not cause pattern fall evenin a pattern with a narrow line in any of the processes.

In addition, it is preferable that mass ratio of the component (A) tothe component (B) satisfies (B)/(A)≧1.

Further, of the constituting units derived from the general formula (3)and the general formula (4) in the component (B), it is preferable thatmole ratio of the constituting unit derived from the general formula (4)is 50% or more by mole.

By using appropriate silicon-containing compounds in the component (A)and the component (B) used in the present invention and selectingappropriate mass ratio thereof as mentioned above, a composition beingcapable of forming a resist underlayer film not only having excellentstorage stability and adhesion but also not changing patterningproperties in both the negative and positive developments can beobtained.

In addition, it is preferable that the U of the general formula (2) isany of boron, aluminum, gallium, yttrium, germanium, titanium,zirconium, hafnium, bismuth, tin, phosphorous, vanadium, arsenic,antimony, niobium, and tantalum.

As mentioned above, by introducing the foregoing elements, optimizationof etching selectivity between the photoresist and the resist underlayerfilm becomes possible so that a composition formable the resistunderlayer film having excellent size stability during dry etching maybe obtained.

In addition, the present invention provides a patterning process,wherein an organic underlayer film is formed on a body to be processedby using an application-type composition for the organic underlayerfilm, on this organic underlayer film is formed a silicon-containingresist underlayer film by using the composition for forming thesilicon-containing resist underlayer film, on this silicon-containingresist underlayer film is formed a photoresist film by using achemically amplified resist composition, the photoresist film is exposedto a high energy beam after heat treatment, a positive pattern is formedby dissolving an exposed area of the photoresist film by using analkaline developer, pattern transfer is made onto the silicon-containingresist underlayer film by dry-etching by using the photoresist filmhaving the positive pattern as a mask, pattern transfer is made onto theorganic underlayer film by dry-etching by using the silicon-containingresist underlayer film having the transferred pattern as a mask, andthen pattern transfer is made onto the body to be processed bydry-etching by using the organic underlayer film having the transferredpattern as a mask.

Further, the present invention provides a patterning process, wherein anorganic hard mask mainly comprising carbon is formed on a body to beprocessed by a CVD method, on this organic hard mask is formed asilicon-containing resist underlayer film by using the composition forforming the silicon-containing resist underlayer film, on thissilicon-containing resist underlayer film is formed a photoresist filmby using a chemically amplified resist composition, the photoresist filmis exposed to a high energy beam after heat treatment, a positivepattern is formed by dissolving an exposed area of the photoresist filmby using an alkaline developer, pattern transfer is made onto thesilicon-containing resist underlayer film by dry-etching by using thephotoresist film having the positive pattern as a mask, pattern transferis made onto the organic hard mask by dry-etching by using thesilicon-containing resist underlayer film having the transferred patternas a mask, and then pattern transfer is made onto the body to beprocessed by dry-etching by using the organic hard mask having thetransferred pattern as a mask.

When patterning is done by a positive development using the compositionof the present invention for a resist underlayer film, by optimizingcombination with the CVD film or the organic underlayer film in the wayas mentioned above, a pattern formed with a photoresist can be formed ona substrate without causing size difference.

In addition, in photo-exposure of the photoresist film, it is preferablethat change of the contact angle in a part of the silicon-containingresist underlayer film corresponding to an unexposed area of the exposedphotoresist film is 10 degree or less as compared with beforephoto-exposure.

If change amount of the contact angle is like this, difference ofcontact angles between an unexposed area of the exposed photoresist filmand a part of the silicon-containing resist underlayer filmcorresponding to this unexposed area of the exposed photoresist filmbecomes 10 degrees or less thereby leading to good adhesion in thepositive development; and as a result, a fine pattern can be formed.

Further, the present invention provides a patterning process, wherein anorganic underlayer film is formed on a body to be processed by using anapplication-type composition for the organic underlayer film, on thisorganic underlayer film is formed a silicon-containing resist underlayerfilm by using the composition for forming the silicon-containing resistunderlayer film, on this silicon-containing resist underlayer film isformed a photoresist film by using a chemically amplified resistcomposition, the photoresist film is exposed to a high energy beam afterheat treatment, a negative pattern is formed by dissolving an unexposedarea of the photoresist film by using an organic solvent developer,pattern transfer is made onto the silicon-containing resist underlayerfilm by dry-etching by using the photoresist film having the negativepattern as a mask, pattern transfer is made onto the organic underlayerfilm by dry-etching by using the silicon-containing resist underlayerfilm having the transferred pattern as a mask, and then pattern transferis made onto the body to be processed by dry-etching by using theorganic underlayer film having the transferred pattern as a mask.

In addition, the present invention provides a patterning process,wherein an organic hard mask mainly comprising carbon is formed on abody to be processed by a CVD method, on this organic hard mask isformed a silicon-containing resist underlayer film by using thecomposition for forming the silicon-containing resist underlayer film,on this silicon-containing resist underlayer film is formed aphotoresist film by using a chemically amplified resist composition, thephotoresist film is exposed to a high energy beam after heat treatment,a negative pattern is formed by dissolving an unexposed area of thephotoresist film by using an organic solvent developer, pattern transferis made onto the silicon-containing resist underlayer film bydry-etching by using the photoresist film having the negative pattern asa mask, pattern transfer is made onto the organic hard mask bydry-etching by using the silicon-containing resist underlayer filmhaving the transferred pattern as a mask, and then pattern transfer ismade onto the body to be processed by dry-etching by using the organichard mask having the transferred pattern as a mask.

When a negative pattern is formed by using the composition of thepresent invention for forming a silicon-containing resist underlayerfilm, by optimizing combination with the CVD film or the organicunderlayer film in the way as mentioned above, a pattern formed with aphotoresist can be formed on a substrate without causing sizedifference.

Further, in photo-exposure of the photoresist film, it is preferablethat the contact angle of a part of the silicon-containing resistunderlayer film corresponding to an exposed area of the exposedphotoresist film is decreased by 10 degrees or more after photo-exposureas compared with before photo-exposure.

The contact angle of the resist pattern after photo-exposure is shiftedtoward a hydrophilic side, i.e., a lower side than before thephoto-exposure; and thus, if the contact angle of the part of thesilicon-containing resist underlayer film corresponding to the exposedarea of the exposed photoresist film is lowered by 10 degrees or more ascompared with before photo-exposure, difference with the contact angleof the resist pattern after the negative development becomes smallthereby enhancing adhesion and prohibiting pattern fall; and as aresult, a fine pattern can be formed.

In addition, in the negative patterning process and the positivepatterning process, it is preferable that the body to be processed is asubstrate for a semiconductor device, or the substrate for asemiconductor device coated, as a layer to be processed, with any of ametal film, a metal carbide film, a metal oxide film, a metal nitridefilm, a metal oxycarbide film, and a metal oxynitride film.

Further, in the negative patterning process and the positive patterningprocess, it is preferable that the metal that constitutes the body to beprocessed is silicon, titanium, tungsten, hafnium, zirconium, chromium,germanium, copper, aluminum, iron, or an alloy of these metals.

According to the patterning process of the present invention, a patterncan be formed by processing the body to be processed as mentioned above.

When the resist underlayer film formed by using the composition of thepresent invention for forming a silicon-containing resist underlayerfilm is used, a resist pattern with excellent adhesion with the resistunderlayer film, without pattern fall and with good surface roughnesscan be obtained in both the positive development (alkaline development)and the negative development (organic solvent development). In addition,in this resist underlayer film, high etching selectivity with an organicmaterial can be obtained; and thus, the formed photoresist pattern canbe transferred successively to the silicon-containing resist underlayerfilm and then to the organic underlayer film or the CVD organic hardmask by using a dry etching process. Especially as the manufacturingprocess of a semiconductor device is progressing toward furtherminiaturization in recent years, in order to prohibit pattern fall afterdevelopment, a thickness of the photoresist film is prone to thinnerwhereby pattern transfer to the resist underlayer film is becomingdifficult. However, if the composition of the present invention forforming a silicon-containing resist underlayer film is used, deformationof the photoresist pattern during dry etching can be suppressed even ifa thin photoresist film is used as an etching mask, so that this patterncan be transferred to a substrate with high precision.

In addition, in practical manufacturing process of a semiconductordevice, all the patterning processes are not changed from the positivedevelopment to the negative development, but only part of an ultrafineprocess is changed; and thus, it may be assumed that the existingpositive development process remains unchanged. In this case, if aresist underlayer film solely dedicated to each the negative developmentand the positive development are used, equipment may become complicatedand quality control may become cumbersome. Accordingly, when acomposition for forming a silicon-containing resist underlayer filmusable in both the positive and the negative processes, like the one inthe present invention, is used, rational management may be possible inboth equipment and quality control.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a flow chart showing one embodiment of a patterning processaccording to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In a positive photoresist, conventionally, film properties of thephotoresist film before photo-exposure and film properties of thepattern formed by an alkaline development after photo-exposure(hereinafter this pattern is called “positive pattern”) have been thesame. And thus, to enhance adhesion of the positive pattern with theresist underlayer film, contact angle of the photoresist to pure waterand contact angle of the resist underlayer film to pure water(hereinafter “contact angle to pure water” is called “contact angle”)were approximated; and this approach has been effective to enhanceadhesion of the positive pattern with the resist underlayer film and tolower the roughness as well.

However, in the pattern obtained by a negative development (hereinafter,this pattern is called “negative pattern”), when comparison is made onfilm properties between the photoresist film before photo-exposure andthe negative pattern after photo-exposure, in the negative pattern, anacid-labile group is eliminated by an acid generated by thephoto-exposure thereby increasing amount of hydrophilic groups such as acarboxyl group and a phenolic hydroxyl group; and as a result, thecontact angle is shifted toward a more hydrophilic side, i.e., a lowerside, than that of the photoresist film before the photo-exposure.Because of this, it was found, in the patterning process in which boththe negative development and the positive development are used, when aconventional resist underlayer film for a positive development whosecontact angle is made coincident with that of a photoresist film beforethe photo-exposure is used as it is, discrepancy from the contact angleof the negative pattern after the photo-exposure is generated therebycausing fall of the negative pattern and an adverse effect in roughness.

Accordingly, inventors of the present invention found that, by utilizingthe fact that the positive pattern is the unexposed photoresist filmarea and the negative pattern is the exposed photoresist film area, ifthe contact angle before the photo-exposure was approximated to thecontact angle of the unexposed photoresist film part to pure water andthe contact angle in the exposed area was approximated to the contactangle of the resist film after the photo-exposure, the resist underlayerfilm having optimum surface conditions in any of the processes could beobtained. With this finding, the inventors carried out extensiveinvestigation on a composition for forming a silicon-containing resistunderlayer film whose contact angle decreases only in the exposed area;and as a result, the inventors found that, when a polymer having anacid-labile group and a polymer not having this group were blended in anappropriate mixing ratio, a composition for forming a silicon-containingresist underlayer film whose contact angle decreased only in the exposedarea could be obtained thereby accomplishing the present invention.

In addition, by controlling the constituting element in the resistunderlayer film containing an organic group which is a driving force tochange the contact angle of the resist underlayer film partcorresponding to the exposed area of the photoresist film, etchingselectivity with the photoresist film could be optimized so that bothetching performance and patterning performance could be satisfied.

In the composition of the present invention for forming asilicon-containing resist underlayer film, when a silicon-containingcompound containing a hydroxyl group or a carboxyl group, the groupsbeing substituted with an acid-labile group, is mixed as the component(A) with a silicon-containing compound having excellent etchingselectivity with the photoresist as the component (B), wherebylocalizing the component (A) on surface of the resist underlayer film,respective optimum surface contact angles during the time of thepositive development and the negative development can be realized.Hereinafter, detailed explanation thereof will be described.

Component (A)

The composition of the present invention for forming asilicon-containing resist underlayer film contains, as the component(A), a silicon-containing compound obtained by a hydrolysis-condensationreaction of a mixture containing, at least, one or more hydrolysablesilicon compound shown by the following general formula (1) and one ormore hydrolysable compound shown by the following general formula (2),R¹ _(m1)R² _(m2)R³ _(m3)Si(OR)_((4-m1-m2-m3))  (1)

wherein, R represents a hydrocarbon group having 1 to 6 carbon atoms;and at least one of R¹, R², and R³ is an organic group containing ahydroxyl group or a carboxyl group, the groups being substituted with anacid-labile group, while the other is a hydrogen atom or a monovalentorganic group having 1 to 30 carbon atoms. m1, m2, and m3 represent 0 or1 and satisfy 1≦m1+m2+m3≦3,U(OR⁴)_(m4)(OR⁵)_(m5)  (2)

wherein, R⁴ and R⁵ represent an organic group having 1 to 30 carbonatoms, and m4+m5 is the same number as the number determined by valencyof U. m4 and m5 represent an integer of 0 or more, and the U is anelement belonging to groups of III, IV, or V in a periodic table exceptfor carbon and silicon.

As to the hydrolysable silicon compound shown by the general formula (1)used as a raw material of the component (A), the compound containing twoor three hydrolysable groups selected from a methoxy group, an ethoxygroup, a propoxy group, and a butoxy group that are bonded to thesilicon atom, as shown in the following structures, may be used.

As to the hydrolysable compound shown by the general formula (2) used asa raw material of the component (A), the followings may be mentioned. Inthe case that the U is boron, illustrative examples of the hydrolysablecompound shown by the general formula (2) include, as monomers, boronmethoxide, boron ethoxide, boron propoxide, boron butoxide, boronamyloxide, boron hexyloxide, boron cyclopentoxide, boron cyclohexloxide,boron allyloxide, boron phenoxide, boron methoxyethoxide, boric acid,and boron oxide.

When U is aluminum, examples of the hydrolysable compound shown by theformula (2) include, as monomers, aluminum methoxide, aluminum ethoxide,aluminum propoxide, aluminum butoxide, aluminum amyloxide, aluminumhexyloxide, aluminum cyclopentoxide, aluminum cyclohexyloxide, aluminumallyloxide, aluminum phenoxide, aluminum methoxyethoxide, aluminumethoxyethoxide, aluminum dipropoxyethyl-acetoacetate, aluminumdibutoxyethyl-acetoacetate, aluminum propoxy-bis-ethyl-acetoacetate,aluminum butoxy-bis-ethyl-acetoacetate, aluminum 2,4-pentanedionate, andaluminum 2,2,6,6-tetramethyl-3,5-heptanedionate.

When U is gallium, examples of the hydrolysable compound shown by theformula (2) include, as monomers, gallium methoxide, gallium ethoxide,gallium propoxide, gallium butoxide, gallium amyloxide, galliumhexyloxide, gallium cyclopentoxide, gallium cyclohexyloxide, galliumallyloxide, gallium phenoxide, gallium methoxyethoxide, galliumethoxyethoxide, gallium dipropoxyethyl-acetoacetate, galliumdibutoxyethyl-acetoacetate, gallium propoxy-bis-ethyl-acetoacetate,gallium butoxy-bis-ethyl-acetoacetate, gallium 2,4-pentanedionate, andgallium 2,2,6,6-tetramethyl-3,5-heptanedionate.

When U is yttrium, examples of the hydrolysable compound shown by theformula (2) include, as monomers, yttrium methoxide, yttrium ethoxide,yttrium propoxide, yttrium butoxide, yttrium amyloxide, yttriumhexyloxide, yttrium cyclopentoxide, yttrium cyclohexyloxide, yttriumallyloxide, yttrium phenoxide, yttrium methoxyethoxide, yttriumethoxyethoxide, yttrium dipropoxyethyl-acetoacetate, yttriumdibutoxyethyl-acetoacetate, yttrium propoxy-bis-ethyl-acetoacetate,yttrium butoxy-bis-ethyl-acetoacetate, yttrium 2,4-pentanedionate, andyttrium 2,2,6,6-tetramethyl-3,5-heptanedionate.

When U is germanium, examples of the hydrolysable compound shown by theformula (2) include, as monomers, germanium methoxide, germaniumethoxide, germanium propoxide, germanium butoxide, germanium amyloxide,germanium hexyloxide, germanium cyclopentoxide, germaniumcyclohexyloxide, germanium allyloxide, germanium phenoxide, germaniummethoxyethoxide, and germanium ethoxyethoxide.

When U is titanium, examples of the hydrolysable compound shown by theformula (2) include, as monomers, titanium methoxide, titanium ethoxide,titanium propoxide, titanium butoxide, titanium amyloxide, titaniumhexyloxide, titanium cyclopentoxide, titanium cyclohexyloxide, titaniumallyloxide, titanium phenoxide, titanium methoxyethoxide, titaniumethoxyethoxide, titanium dipropoxy-bisethyl-acetoacetate, titaniumdibutoxy-bisethyl-acetoacetate, titaniumdipropoxy-bis-2,4-pentanedionate, and titaniumdibutoxy-bis-2,4-pentanedionate.

When U is hafnium, examples of the hydrolysable compound shown by theformula (2) include, as monomers, hafnium methoxide, hafnium ethoxide,hafnium propoxide, hafnium butoxide, hafnium amyloxide, hafniumhexyloxide, hafnium cyclopentoxide, hafnium cyclohexyloxide, hafniumallyloxide, hafnium phenoxide, hafnium methoxyethoxide, hafniumethoxyethoxide, hafnium dipropoxy-bisethyl-acetoacetate, hafniumdibutoxy-bisethyl-acetoacetate, hafniumdipropoxy-bis-2,4-pentanedionate, and hafniumdibutoxy-bis-2,4-pentanedionate.

When U is tin, examples of the hydrolysable compound shown by theformula (2) include, as monomers, methoxy tin, ethoxy tin, propoxy tin,butoxy tin, phenoxy tin, methoxyethoxy tin, ethoxyethoxy tin, tin2,4-pentanedionate, and tin 2,2,6,6-tetramethyl-3,5-heptanedionate.

When U is arsenic, examples of the hydrolysable compound shown by theformula (2) include, as monomers, methoxy arsenic, ethoxy arsenic,propoxy arsenic, butoxy arsenic, and phenoxy arsenic.

When U is antimony, examples of the hydrolysable compound shown by theformula (2) include, as monomers, methoxy antimony, ethoxy antimony,propoxy antimony, butoxy antimony, phenoxy antimony, antimony acetate,and antimony propionate.

When U is niobium, examples of the hydrolysable compound shown by theformula (2) include, as monomers, methoxy niobium, ethoxy niobium,propoxy niobium, butoxy niobium, and phenoxy niobium.

When U is tantalum, examples of the hydrolysable compound shown by theformula (2) include, as monomers, methoxy tantalum, ethoxy tantalum,propoxy tantalum, butoxy tantalum, and phenoxy tantalum.

When U is bismuth, examples of the hydrolysable compound shown by theformula (2) include, as monomers, methoxy bismuth, ethoxy bismuth,propoxy bismuth, butoxy bismuth, and phenoxy bismuth.

When U is phosphorus, examples of the compounds represented by theformula (2) include, as monomers, trimethyl phosphite, triethylphosphite, tripropyl phosphite, and diphosphorus pentoxide.

When U is vanadium, examples of the compounds represented by the formula(2) include, as monomers, vanadium oxide-bis(2,4-pentanedionate),vanadium 2,4-pentanedionate, vanadium tributoxide oxide, and vanadiumtripropoxide oxide.

When U is zirconium, examples of the compounds represented by theformula (2) include, as monomers, methoxy zirconium, ethoxy zirconium,propoxy zirconium, butoxy zirconium, phenoxy zirconium, zirconiumdibutoxide-bis(2,4-pentanedionate), and zirconiumdipropoxide-bis(2,2,6,6-tetramethyl-3,5-heptanedionate).

In the present invention, by introducing the foregoing elements as U ofthe general formula (2), etching selectivity between the photoresistfilm and the resist underlayer film formed by the composition of thepresent invention can be optimized; and as a result, a compositionformable the resist underlayer film having excellent size stabilityduring processing by dry etching can be obtained.

In addition, compounds shown by the general formulae (3) and (4) used asraw materials of the component (B) as mentioned later may be used as apart of raw materials of the component (A).

Amount of the general formula (1) in the component (A) is preferably 5%or more by mole, or more preferably 10% or more by mole. Amount of thegeneral formula (2) in the component (A) is preferably 10% or more bymole, or more preferably 20% or more by mole. Amount of the generalformulae (1) and (2) in the component (A) is preferably 50% or more bymole, or more preferably 55% or more by mole.

Component (B)

The composition of the present invention for forming asilicon-containing resist underlayer film contains, as the component(B), a silicon-containing compound obtained by a hydrolysis-condensationreaction of a mixture containing, at least, one or more hydrolysablesilicon compound shown by the following general formula (3) and one ormore hydrolysable silicon compound shown by the following generalformula (4). Component (B) is not particularly restricted, but thecomponent preferably does not contain a hydroxyl group or a carboxylgroup, the groups being substituted with an acid-labile group,R⁶ _(m6)R⁷ _(m7)R⁸ _(m8)Si(OR⁹)_((4-m6-m7-m8))  (3)

wherein, R⁹ represents an alkyl group having 1 to 6 carbon atoms, andeach R⁶, R⁷, and R⁸ represents a hydrogen atom or a monovalent organicgroup having 1 to 30 carbon atoms. m6, m7, and m8 represent 0 or 1 andsatisfy 1≦m6+m7+m8≦3,Si(OR¹⁰)₄  (4)

wherein, R¹⁰ represents an alkyl group having 1 to 6 carbon atoms.

As to the compound shown by the general formula (3) used as a rawmaterial of the component (B), following compounds may be mentioned asillustrative examples thereof.

Examples thereof include trimethoxysilane, triethoxysilane,tripropoxysilane, triisopropoxysilane, methyltrimethoxysilane,methyltriethoxysilane, methyltripropoxysilane,methyltriisopropoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane,ethyltripropoxysilane, ethyltriisopropoxysilane, vinyltrimethoxysilane,vinyltriethoxysilane, vinyltripropoxysilane, vinyltriisopropoxysilane,propyltrimethoxysilane, propyltriethoxysilane, propyltripropoxysilane,propyltriisopropoxysilane, isopropyltrimethoxysilane,isopropyltriethoxysilane, isopropyltripropoxysilane,isopropyltriisopropoxysilane, butyltrimethoxysilane,butyltriethoxysilane, butyltripropoxysilane, butyltriisopropoxysilane,sec-butyltrimethoxysilane, sec-butyltriethoxysilane,sec-butyltripropoxysilane, sec-butyltriisopropoxysilane,t-butyltrimethoxysilane, t-butyltriethoxysilane,t-butyltripropoxysilane, t-butyltriisopropoxysilane,cyclopropyltrimethoxysilane, cyclopropyltriethoxysilane,cyclopropyltripropoxysilane, cyclopropyltriisopropoxysilane,cyclobutyltrimethoxysilane, cyclobutyltriethoxysilane,cyclobutyltripropoxysilane, cyclobutyltriisopropoxysilane,cyclopentyltrimethoxysilane, cyclopentyltriethoxysilane,cyclopentyltripropoxysilane, cyclopentyltriisopropoxysilane,cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane,cyclohexyltripropoxysilane, cyclohexyltriisopropoxysilane,cyclohexenyltrimethoxysilane, cyclohexenyltriethoxysilane,cyclohexenyltripropoxysilane, cyclohexenyltriisopropoxysilane,cyclohexenylethyltrimethoxysilane, cyclohexenylethyltriethoxysilane,cyclohexenylethyltripropoxysilane, cyclohexenylethyltriisopropoxysilane,cyclooctyltrimethoxysilane, cyclooctyltriethoxysilane,cyclooctyltripropoxysilane, cyclooctyltriisopropoxysilane,cyclopentadienylpropyltrimethoxysilane,cyclopentadienylpropyltriethoxysilane,cyclopentadienylpropyltripropoxysilane,cyclopentadienylpropyltriisopropoxysilane,bicycloheptenyltrimethoxysilane, bicycloheptenyltriethoxysilane,bicycloheptenyltripropoxysilane, bicycloheptenyltriisopropoxysilane,bicycloheptyltrimethoxysilane, bicycloheptyltriethoxysilane,bicycloheptyltripropoxysilane, bicycloheptyltriisopropoxysilane,adamantyltrimethoxysilane, adamantyltriethoxysilane,adamantyltripropoxysilane, adamantyltriisopropoxysilane,phenyltrimethoxysilane, phenyltriethoxysilane, phenyltripropoxysilane,phenyltriisopropoxysilane, benzyltrimethoxysilane,benzyltriethoxysilane, benzyltripropoxysilane,benzyltriisopropoxysilane, anisyltrimethoxysilane,anisyltriethoxysilane, anisyltripropoxysilane,anisyltriisopropoxysilane, tolyltrimethoxysilane, tolyltriethoxysilane,tolyltripropoxysilane, tolyltriisopropoxysilane,phenethyltrimethoxysilane, phenethyltriethoxysilane,phenethyltripropoxysilane, phenethyltriisopropoxysilane,naphthyltrimethoxysilane, naphthyltriethoxysilane,naphthyltripropoxysilane, naphthyltriisopropoxysilane,dimethyldimethoxysilane, dimethyldiethoxysilane,methylethyldimethoxysilane, methylethyldiethoxysilane,dimethyldipropoxysilane, dimethyldiisopropoxysilane,diethyldimethoxysilane, diethyldiethoxysilane, diethyldipropoxysilane,diethyldiisopropoxysilane, dipropyldimethoxysilane,dipropyldiethoxysilane, dipropyldipropoxysilane,dipropyldiisopropoxysilane, diisopropyldimethoxysilane,diisopropyldiethoxysilane, diisopropyldipropoxysilane,diisopropyldiisopropoxysilane, dibutyldimethoxysilane,dibutyldiethoxysilane, dibutyldipropoxysilane,dibutyldiisopropoxysilane, di-sec-butyldimethoxysilane,di-sec-butyldiethoxysilane, di-sec-butyldipropoxysilane,di-sec-butyldiisopropoxysilane, di-t-butyldimethoxysilane,di-t-butyldiethoxysilane, di-t-butyldipropoxysilane,di-t-butyldiisopropoxysilane, dicyclopropyldimethoxysilane,dicyclopropyldiethoxysilane, dicyclopropyldipropoxysilane,dicyclopropyldiisopropoxysilane, dicyclobutyldimethoxysilane,dicyclobutyldiethoxysilane, dicyclobutyldipropoxysilane,dicyclobutyldiisopropoxysilane, dicyclopentyldimethoxysilane,dicyclopentyldiethoxysilane, dicyclopentyldipropoxysilane,dicyclopentyldiisopropoxysilane, dicyclohexyldimethoxysilane,dicyclohexyldiethoxysilane, dicyclohexyldipropoxysilane,dicyclohexyldiisopropoxysilane, dicyclohexenyldimethoxysilane,dicyclohexenyldiethoxysilane, dicyclohexenyldipropoxysilane,dicyclohexenyldiisopropoxysilane, dicyclohexenylethyldimethoxysilane,dicyclohexenylethyldiethoxysilane, dicyclohexenylethyldipropoxysilane,dicyclohexenylethyldiisopropoxysilane, dicyclooctyldimethoxysilane,dicyclooctyldiethoxysilane, dicyclooctyldipropoxysilane,dicyclooctyldiisopropoxysilane, dicyclopentadienylpropyldimethoxysilane,dicyclopentadienylpropyldiethoxysilane,dicyclopentadienylpropyldipropoxysilane,dicyclopentadienylpropyldiisopropoxysilane,bisbicycloheptenyldimethoxysilane, bisbicycloheptenyldiethoxysilane,bisbicycloheptenyldipropoxysilane, bisbicycloheptenyldiisopropoxysilane,bisbicycloheptyldimethoxysilane, bisbicycloheptyldiethoxysilane,bisbicycloheptyldipropoxysilane, bisbicycloheptyldiisopropoxysilane,diadamantyldimethoxysilane, diadamantyldiethoxysilane,diadamantyldipropoxysilane, diadamantyldiisopropoxysilane,diphenyldimethoxysilane, diphenyldiethoxysilane,methylphenyldimethoxysilane, methylphenyldiethoxysilane,diphenyldipropoxysilane, diphenyldiisopropoxysilane,trimethylmethoxysilane, trimethylethoxysilane,dimethylethylmethoxysilane, dimethylethylethoxysilane,dimethylphenylmethoxysilane, dimethylphenylethoxysilane,dimethylbenzylmethoxysilane, dimethylbenzylethoxysilane,dimethylphenethylmethoxysilane, and dimethylphenethylethoxysilane.

Examples of the compound shown by the general formula (4) used as a rawmaterial of the component (B) include tetramethoxysilane,tetraethoxysilane, tetrapropoxysilane, tetraisopropoxysilane.

Preferable examples among them include tetramethoxysilane,tetraethoxysilane methyltrimethoxysilane, methyltriethoxysilane,ethyltrimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane,vinyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane,isopropyltrimethoxysilane, isopropyltriethoxysilane,butyltrimethoxysilane, butyltriethoxysilane, isobutyltrimethoxysilane,isobutyltriethoxysilane, allyltrimethoxysilane, allyltriethoxysilane,cyclopentyltrimethoxysilane, cyclopentyltriethoxysilane,cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane,cyclohexenyltrimethoxysilane, cyclohexenyltriethoxysilane,phenyltrimethoxysilane, phenyltriethoxysilane, benzyltrimethoxysilane,benzyltriethoxysilane, toryltrimethoxysilane, toryltriethoxysilane,anisyltrimethoxysilane, anisyltriethoxysilane,phenethyltrimethoxysilane, phenethyltriethoxysilane,dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane,diethyldiethoxysilane, methylethyldimethoxysilane,methylethyldiethoxysilane, dipropyldimethoxysilane,dibutyldimethoxysilane, methylphenyldimethoxysilane,methylphenyldiethoxysilane, trimethylmethoxysilane,dimethylethylmethoxysilane, dimethylphenylmethoxysilane,dimethylbenzylmethoxysilane, and dimethylphenethylmethoxysilane.

Of the constituting units derived from the general formula (3) and thegeneral formula (4) in the component (B), mole ratio of the constitutingunit derived from the general formula (4) is preferably 50% or more bymole, or more preferably 55% or more by mole. In addition, mass ratio ofthe component (A) to the component (B) is preferably (B)/(A)≧1. When thesilicon-containing compounds used in the present invention are selectedproperly and used with proper mass ratio as mentioned above, acomposition being capable of forming a silicon-containing resistunderlayer film not only having excellent storage stability and adhesionproperty but also not changing patterning performance during thenegative development and the positive development can be obtained.

Synthesis Methods of the Silicon-Containing Compounds

Raw material for the reaction to form the component (A) and thecomponent (B) may be prepared by mixing, prior to or during thereaction, one or more compounds shown by the general formulae (1) to (4)(hereinafter, these compounds are merely called “monomer”). Hereinafter,the components (A) and (B) are collectively called “silicon-containingcompound”.

(Synthesis Method 1: Acid Catalyst)

The silicon-containing compound of the present invention can beproduced, by conducting hydrolytic condensation between monomers, whileadopting, as an acid catalyst, one or more kinds of compounds selectedfrom inorganic acids, aliphatic sulfonic acids, and aromatic sulfonicacids.

Examples of the acid catalyst to be used at this time includehydrofluoric acid, hydrochloric acid, hydrobromic acid, sulfuric acid,nitric acid, perchloric acid, phosphoric acid, methanesulfonic acid,benzenesulfonic acid, and toluenesulfonic acid. The catalyst is used inan amount of 10⁻⁶ to 10 moles, preferably 10⁻⁵ to 5 moles, morepreferably 10⁻⁴ to 1 mole, relative to 1 mole of monomers.

The amount of water upon obtainment of the silicon-containing compoundfrom these monomers by hydrolytic condensation, is 0.01 to 100 moles,preferably 0.05 to 50 moles, and more preferably 0.1 to 30 moles, permole of hydrolyzable substitutional groups bonded to the monomers.Addition amounts 100 moles or less are economical, due to small-sizedapparatuses to be used for reactions.

As a manipulation manner, the monomers are added into an aqueouscatalyst solution, to cause initiation of a hydrolytic condensationreaction. At this time, the organic solvent may be added into theaqueous catalyst solution, or monomers may have been diluted with theorganic solvent, or both procedures may be performed. The reactiontemperature is to be 0 to 100° C., preferably 5 to 80° C. It is apreferable manner to keep the temperature at 5 to 80° C. upon droppingof the monomers, and subsequently mature them at 20 to 80° C.

Preferable examples of organic solvents, which can be added into theaqueous catalyst solution or which can dilute the monomers, includemethanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol,2-methyl-1-propanol, acetone, acetonitrile, tetrahydrofuran, toluene,hexane, ethyl acetate, cyclohexanone, methylamylketone, butane diolmonomethyl ether, propylene glycol monomethyl ether, ethylene glycolmonomethyl ether, butane diol monoethyl ether, propylene glycolmonoethyl ether, ethylene glycol monoethyl ether, propylene glycoldimethyl ether, diethylene glycol dimethyl ether, propylene glycolmonomethyl ether acetate, propylene glycol monoethyl ether acetate,ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, propyleneglycol mono-tert-butyl ether acetate, γ-butyrolactone, and mixtures ofthem.

Water-soluble ones are preferable among them. Examples thereof include:alcohols such as methanol, ethanol, 1-propanol, and 2-propanol;polyvalent alcohols such as ethylene glycol and propylene glycol;polyvalent alcohol condensation derivatives such as butane diolmonomethyl ether, propylene glycol monomethyl ether, ethylene glycolmonomethyl ether, butane diol monoethyl ether, propylene glycolmonoethyl ether, ethylene glycol monoethyl ether, butane diol monopropylether, propylene glycol monopropyl ether, and ethylene glycol monopropylether; acetone; acetonitrile; and tetrahydrofuran. Those having boilingpoints of 100° C. or lower are especially preferable among them.

Meanwhile, amount of the organic solvent to be used is preferably in therange of 0 to 1000 mL, or in particular 0 to 500 mL, relative to onemole of the monomer. Smaller amount of the organic solvent is moreeconomical because a reactor volume becomes smaller.

Thereafter, neutralization reaction of the catalyst is conducted ifnecessary, thereby obtaining an aqueous solution of reaction mixture. Atthis time, the amount of an alkaline substance usable for neutralizationis preferably 0.1 to 2 equivalents relative to the acid used as thecatalyst. This alkaline substance is arbitrary, insofar as the sameexhibits alkalinity in water.

Subsequently, it is preferable to remove, from the reaction mixture, aby-product such as an alcohol formed by the hydrolysis condensationreaction by such a method as distillation under reduced pressure. Inthis removal procedure, a temperature to heat the reaction mixture ispreferably 0 to 100° C., more preferably 10 to 90° C., or still morepreferably 15 to 80° C., though depending on the organic solvent added,the alcohol formed by the reaction, and the like. The degree ofevacuation during the removal procedure is preferably below anatmospheric pressure, more preferably 80 or less kPa by absolutepressure, or still more preferably 50 or less kPa by absolute pressure,though different depending on an exhausting equipment, a condensationequipment, a heating temperature, and an organic solvent, an alcohol,and the like to be removed. During this procedure, it is preferable thatabout 80% or more by mass of the total alcohol and the like formed isremoved, though it is difficult to know exactly the amount of removedalcohol.

Next, it is possible to remove the acid catalyst used for the hydrolyticcondensation, from the reaction mixture. As a procedure for removing theacid catalyst, the reaction mixture is mixed with water, and thesilicon-containing compound is extracted with an organic solvent.Suitable as an organic solvent to be used then, is one which allows fordissolution of the silicon-containing compound therein and which isseparated in a two-layered manner from water upon mixing therewith.Examples thereof include methanol, ethanol, 1-propanol, 2-propanol,1-butanol, 2-butanol, 2-methyl-1-propanol, acetone, tetrahydrofuran,toluene, hexane, ethyl acetate, cyclohexanone, methylamylketone, butanediol monomethyl ether, propylene glycol monomethyl ether, ethyleneglycol monomethyl ether, butane diol monoethyl ether, propylene glycolmonoethyl ether, ethylene glycol monoethyl ether, butane diol monopropylether, propylene glycol monopropyl ether, ethylene glycol monopropylether, propylene glycol dimethyl ether, diethylene glycol dimethylether, propylene glycol monomethyl ether acetate, propylene glycolmonoethyl ether acetate, ethyl pyruvate, butyl acetate, methyl3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate,tert-butyl propionate, propylene glycol mono-tert-butyl ether acetate,γ-butyrolactone, methyl isobutyl ketone, cyclopentyl methyl ether, andmixtures thereof.

It is also possible to use a mixture of a water-soluble organic solventand a water hardly-soluble organic solvent. Examples of preferablemixtures include, without limited thereto, combinations ofmethanol+ethyl acetate, ethanol+ethyl acetate, 1-propanol+ethyl acetate,2-propanol+ethyl acetate, butane diol monomethyl ether+ethyl acetate,propylene glycol monomethyl ether+ethyl acetate, ethylene glycolmonomethyl ether+ethyl acetate, butane diol monoethyl ether+ethylacetate, propylene glycol monoethyl ether+ethyl acetate, ethylene glycolmonoethyl ether+ethyl acetate, butane diol monopropyl ether+ethylacetate, propylene glycol monopropyl ether+ethyl acetate, ethyleneglycol monopropyl ether+ethyl acetate, methanol+methyl isobutyl ketone,ethanol+methyl isobutyl ketone, 1-propanol+methyl isobutyl ketone,2-propanol+methyl isobutyl ketone, propylene glycol monomethylether+methyl isobutyl ketone, ethylene glycol monomethyl ether+methylisobutyl ketone, propylene glycol monoethyl ether+methyl isobutylketone, ethylene glycol monoethyl ether+methyl isobutyl ketone,propylene glycol monopropyl ether+methyl isobutyl ketone, ethyleneglycol monopropyl ether+methyl isobutyl ketone, methanol+cyclopentylmethyl ether, ethanol+cyclopentyl methyl ether, 1-propanol+cyclopentylmethyl ether, 2-propanol+cyclopentyl methyl ether, propylene glycolmonomethyl ether+cyclopentyl methyl ether, ethylene glycol monomethylether+cyclopentyl methyl ether, propylene glycol monoethylether+cyclopentyl methyl ether, ethylene glycol monoethylether+cyclopentyl methyl ether, propylene glycol monopropylether+cyclopentyl methyl ether, ethylene glycol monopropylether+cyclopentyl methyl ether, methanol+propylene glycol methyl etheracetate, ethanol+propylene glycol methyl ether acetate,1-propanol+propylene glycol methyl ether acetate, 2-propanol+propyleneglycol methyl ether acetate, propylene glycol monomethyl ether+propyleneglycol methyl ether acetate, ethylene glycol monomethyl ether+propyleneglycol methyl ether acetate, propylene glycol monoethyl ether+propyleneglycol methyl ether acetate, ethylene glycol monoethyl ether+propyleneglycol methyl ether acetate, propylene glycol monopropyl ether+propyleneglycol methyl ether acetate, and ethylene glycol monopropylether+propylene glycol methyl ether acetate.

Note that although the mixing ratio of the water-soluble organic solventand the water hardly-soluble organic solvent is to be appropriatelyselected, the water-soluble organic solvent is selected to be 0.1 to1,000 parts by mass, preferably 1 to 500 parts by mass, more preferably2 to 100 parts by mass, relative to 100 parts by mass of the waterhardly-soluble organic solvent.

The procedure is followed by washing by neutral water. Usable as suchneutral water is so-called deionized water or ultrapure water. Theamount of such water is to be 0.01 to 100 L, preferably 0.05 to 50 L,and more preferably 0.1 to 5 L, relative to 1 L of thesilicon-containing compound solution. The washing procedure may beconducted by introducing both liquids into one vessel, stirring them,and then leaving them to stand still, followed by separation of a waterlayer. It is enough for the number of washing steps to be one or more,preferably one to about five, because commensurate effects are notobtained even by washing of ten or more times.

Other examples of methods for removing the acid catalyst include amethod based on an ion-exchange resin, and a method for conductingneutralization by epoxy compounds such as ethylene oxide and propyleneoxide followed by removal. These methods can be appropriately selectedin conformity to the acid catalyst for the reaction.

Since a part of the silicon-containing compound is sometimes migratedinto a water layer by the washing operation at this time to provide aneffect substantially equivalent to a fractionation, the number ofwashing times and the amount of washing water may be appropriatelyselected in view of the catalyst removal effect and fractionationeffect.

In both cases of a silicon-containing compound including the acidcatalyst left therein and a silicon-containing compound solution fromwhich the acid catalyst has been removed, a final solvent is addedthereto, and solvent exchange is conducted under reduced pressure, toobtain a resultant silicon-containing compound solution. Although thetemperature for solvent exchange depends on the types of reactionsolvent, extraction solvent and the like to be removed, the temperatureis preferably 0 to 100° C., more preferably 10 to 90° C., and even morepreferably 15 to 80° C. Further, although the reduced pressure variesdepending on the type of extraction solvent to be removed, types ofevacuating apparatus and condensation apparatus, and the heatingtemperature, the reduced pressure is preferably at the atmosphericpressure or lower, more preferably 80 kPa or lower in absolute pressure,and even more preferably 50 kPa or lower in absolute pressure.

In this process, there is a case that exchange of the solvent causesdestabilization of the silicon-containing compound. This destabilizationis caused by incompatibility of the silicon-containing compound with thefinal solvent; and to prohibit this, a monovalent, or a divalent orhigher alcohol having a cyclic ether substituent described in paragraphs(0181) to (0182) of Japanese Patent Laid-Open (kokai) No. 2009-126940may be added as a stabilizer. Adding amount thereof is 0 to 25 parts bymass, preferably 0 to 15 parts by mass, or still more preferably 0 to 5parts by mass, relative to 100 parts by mass of the silicon-containingcompound in the solution before the solvent exchange; in the case thatthis is added, the amount thereof is preferably 0.5 or more parts bymass. If necessary, solvent exchange may be carried out after amonovalent, or a divalent or higher alcohol having a cyclic ethersubstituent is added into the solution before the solvent exchange.

There is a fear that the silicon-containing compound goes on thecondensation reaction when it is concentrated above a certainconcentration level whereby the compound is changed to the state notredissolvable into an organic solvent; and thus, it is desirable tomaintain the state of solution having a proper concentration. If theconcentration thereof is too dilute, amount of the solvent becomesexcessively large; and thus, the state of solution having a properconcentration is desirable in view of economy. Concentration at thistime is preferably 0.1 to 20% by mass.

Suitable as a final solvent to be added to the silicon-containingcompound solution is an alcohol-based solvent, and particularlydesirable examples thereof include monoalkyl ether derivatives of:ethylene glycol, diethylene glycol, triethylene glycol, propyleneglycol, dipropylene glycol, and butanediol. Preferable examplesconcretely include butane diol monomethyl ether, propylene glycolmonomethyl ether, ethylene glycol monomethyl ether, butane diolmonoethyl ether, propylene glycol monoethyl ether, ethylene glycolmonoethyl ether, butane diol monopropyl ether, propylene glycolmonopropyl ether, and ethylene glycol monopropyl ether.

Alternatively, in the case that the alcohol-based solvents are maincomponents, a non-alcoholic solvent may be added as a supplementalsolvent. Examples of this supplemental solvents include acetone,tetrahydrofurane, toluene, hexane, ethyl acetate, cyclohexanone,methylamyl ketone, propylene glycol dimethyl ether, diethylene glycoldimethyl ether, propylene glycol monomethyl ether acetate, propyleneglycol monoethyl ether acetate, ethyl pyruvate, butyl acetate, methyl3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate,tert-butyl propionate, propylene glycol mono-tert-butyl ether acetate,γ-butyrolactone, methyl isobutyl ketone, and cyclopentyl methyl ether.

As another operation for reaction by using an acid catalyst, water orwater-containing organic solvent is added to the monomers or an organicsolution of monomers, to initiate a hydrolysis reaction. At this time,the catalyst may be added to the monomers or the organic solution ofmonomers, or may have been added into water or the water-containingorganic solvent. The reaction temperature is to be 0 to 100° C.,preferably 10 to 80° C. It is a preferable procedure to conduct heatingto 10 to 50° C. upon dropping of water, and to subsequently raise thetemperature to 20 to 80° C. for maturation.

In case of using organic solvents, water-soluble ones are preferable,and examples thereof include methanol, ethanol, 1-propanol, 2-propanol,1-butanol, 2-butanol, 2-methyl-1-propanol, acetone, tetrahydrofuran,acetonitrile; polyvalent alcohol condensate derivatives such as: butanediol monomethyl ether, propylene glycol monomethyl ether, ethyleneglycol monomethyl ether, butane diol monoethyl ether, propylene glycolmonoethyl ether, ethylene glycol monoethyl ether, butane diol monopropylether, propylene glycol monopropyl ether, ethylene glycol monopropylether, propylene glycol dimethyl ether, diethylene glycol dimethylether, propylene glycol monomethyl ether acetate, propylene glycolmonoethyl ether acetate, and propylene glycol monopropyl ether; andmixtures thereof.

Amount of the organic solvent to be used is preferably in the range of 0to 1,000 mL, or in particular 0 to 500 mL, relative to one mole of themonomer. Smaller amount of the organic solvent is more economicalbecause a reactor volume becomes smaller. Work-up of the reactionmixture obtained is done, in a manner similar to that of the previouslymentioned, to obtain the intended silicon-containing compound.

Synthesis Method 2: Base Catalyst

The silicon-containing compound can be produced by ahydrolysis-condensation reaction of monomers in the presence of a basecatalyst. Illustrative examples of the base catalyst to be used in thereaction include methylamine, ethylamine, propylamine, butylamine,ethylene diamine, hexamethylene diamine, dimethylamine, diethylamine,ethylmethylamine, trimethylamine, triethylamine, tripropylamine,tributylamine, cyclohexylamine, dicyclohexylamine, monoethanolamine,diethanolamine, dimethyl monoethanolamine, monomethyl diethanolamine,triethanolamine, diazabicyclooctane, diazabicyclononene,diazabicycloundecene, hexamethylene tetramine, aniline,N,N-dimethylaniline, pyridine, N,N-dimethylaminopyridine, pyrrole,piperazine, pyrrolidine, piperidine, picoline, tetramethylammoniumhydroxide, corrin hydroxide, tetrapropylammonium hydroxide,tetrabutylammonium hydroxide, ammonia, lithium hydroxide, sodiumhydroxide, potassium hydroxide, barium hydroxide, and calcium hydroxide.Amount of the catalyst to be used is 1×10⁻⁶ to 10 mole, preferably1×10⁻⁵ to 5 mole, or more preferably 1×10⁻⁴ to 1 mole, relative to onemole of the silicon monomer.

The amount of water upon obtainment of the silicon-containing compoundfrom these monomers by hydrolytic condensation, is preferably 0.1 to 50moles per mole of hydrolyzable substitutional groups bonded to themonomers. Addition amounts 50 moles or less are economical, due tosmall-sized apparatuses to be used for reactions.

As a manipulation manner, the monomers are added into an aqueouscatalyst solution, to cause initiation of a hydrolytic condensationreaction. At this time, the organic solvent may be added into theaqueous catalyst solution, or monomers may have been diluted with theorganic solvent, or both procedures may be performed. The reactiontemperature is to be 0 to 100° C., preferably 5 to 80° C. It is apreferable manner to keep the temperature at 5 to 80° C. upon droppingof the monomers, and subsequently mature them at 20 to 80° C.

As to the organic solvent that can be added to the aqueous base catalystsolution or can dilute the monomers, the same organic solvents as thoseillustrated as the example that can be added to the aqueous acidcatalyst solution may be used preferably. Meanwhile, in view of carryingout the reaction economically, amount of the organic solvent to be usedis preferably 0 to 1000 mL relative to one mole of the monomer.

Thereafter, neutralization reaction of the catalyst is conducted ifnecessary, thereby obtaining an aqueous solution of reaction mixture. Atthis time, the amount of an acidic substance usable for neutralizationis preferably 0.1 to 2 equivalents relative to the basic material usedas the catalyst. This acidic substance is arbitrary, insofar as the sameexhibits acidity in water.

Subsequently, it is preferable to remove, from the reaction mixture, aby-product such as an alcohol formed by the hydrolysis condensationreaction by such a method as distillation under reduced pressure. Inthis removal procedure, a temperature to heat the reaction mixture ispreferably 0 to 100° C., more preferably 10 to 90° C., or still morepreferably 15 to 80° C., though depending on the organic solvent added,the alcohol formed by the reaction, and the like. The degree ofevacuation during the removal procedure is preferably below anatmospheric pressure, more preferably 80 or less kPa by absolutepressure, or still more preferably 50 or less kPa by absolute pressure,though different depending on an exhausting equipment, a condensationequipment, a heating temperature, and an organic solvent, an alcohol,and the like to be removed. During this procedure, it is preferable thatabout 80% or more by mass of the total alcohol and the like formed isremoved, though it is difficult to know exactly the amount of removedalcohol.

Then, in order to remove the base catalyst used in thehydrolysis-condensation reaction, the silicon-containing compound isextracted by an organic solvent. As to the organic solvent to be usedfor this operation, a solvent that can dissolve the silicon-containingcompound and can be separated into two layers when mixed with water isdesirable. Alternatively, a mixture of a water-soluble organic solventand a water-insoluble organic solvent may also be used.

Specific examples of the organic solvent to be used for removal of thebase catalyst include those organic solvents mentioned before as thespecific examples in removal of the acid catalyst and those similar tothe mixture of a water-soluble organic solvent and a water-insolubleorganic solvent.

Note that although the mixing ratio of the water-soluble organic solventand the water hardly-soluble organic solvent is to be appropriatelyselected, the water-soluble organic solvent is selected to be 0.1 to1,000 parts by mass, preferably 1 to 500 parts by mass, more preferably2 to 100 parts by mass, relative to 100 parts by mass of the waterhardly-soluble organic solvent.

The procedure is followed by washing by neutral water. Usable as suchneutral water is so-called deionized water or ultrapure water. Theamount of such water is to be 0.01 to 100 L, preferably 0.05 to 50 L,and more preferably 0.1 to 5 L, relative to 1 L of thesilicon-containing compound solution. The washing procedure may beconducted by introducing both liquids into one vessel, stirring them,and then leaving them to stand still, followed by separation of a waterlayer. It is enough for the number of washing steps to be one or more,preferably one to about five, because commensurate effects are notobtained even by washing of ten or more times.

A final solvent is added to the silicon-containing compound solutionfrom which the acid catalyst has been removed, and solvent exchange isconducted under reduced pressure, to obtain a resultantsilicon-containing compound solution. Although the temperature forsolvent exchange depends on the types of extraction solvent and the liketo be removed, the temperature is preferably 0 to 100° C., morepreferably 10 to 90° C., and even more preferably 15 to 80° C. Further,although the reduced pressure varies depending on the type of extractionsolvent to be removed, types of evacuating apparatus and condensationapparatus, and the heating temperature, the reduced pressure ispreferably at the atmospheric pressure or lower, more preferably 80 kPaor lower in absolute pressure, and even more preferably 50 kPa or lowerin absolute pressure.

Suitable as a final solvent to be added to the silicon-containingcompound solution is an alcohol-based solvent, and particularlydesirable examples thereof include monoalkyl ether derivatives of:ethylene glycol, diethylene glycol, triethylene glycol, propyleneglycol, and dipropylene glycol. Preferable examples concretely includepropylene glycol monomethyl ether, ethylene glycol monomethyl ether,propylene glycol monoethyl ether, ethylene glycol monoethyl ether,propylene glycol monopropyl ether, and ethylene glycol monopropyl ether.

As another operation for reaction by using a base catalyst, water orwater-containing organic solvent is added to the monomers or an organicsolution of monomers, to initiate a hydrolysis reaction. At this time,the catalyst may be added to the monomers or the organic solution ofmonomers, or may have been added into water or the water-containingorganic solvent. The reaction temperature is to be 0 to 100° C.,preferably 10 to 80° C. It is a preferable procedure to conduct heatingto 10 to 50° C. upon dropping of water, and to subsequently raise thetemperature to 20 to 80° C. for maturation.

The organic solvents, which can be used as organic solution of monomersor which can be used as the water-containing organic solvent, arepreferably water-soluble one. Examples thereof include methanol,ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol,2-methyl-1-propanol, acetone, tetrahydrofuran, acetonitrile; andpolyvalent alcohol condensate derivatives such as: propylene glycolmonomethyl ether, ethylene glycol monomethyl ether, propylene glycolmonoethyl ether, ethylene glycol monoethyl ether, propylene glycolmonopropyl ether, ethylene glycol monopropyl ether, propylene glycoldimethyl ether, diethylene glycol dimethyl ether, propylene glycolmonomethyl ether acetate, propylene glycol monoethyl ether acetate, andpropylene glycol monopropyl ether; and mixtures thereof.

Although the molecular weight of the silicon-containing compoundobtained by the synthesis method 1 or 2 can be adjusted not only byselection of monomers but also by control of reaction condition uponpolymerization, adoption of compounds having weight-average molecularweights exceeding 100,000 occasionally cause occurrence of extraneoussubstances or coating patch, so that those compounds are to bepreferably used which have weight-average molecular weights of 100,000or less, preferably 200 to 50,000, and more preferably 300 to 30,000,respectively. Note that the data concerning the weight-average molecularweight is obtained as a molecular weight determined by gel permeationchromatography (GPC) using an RI detector, polystyrene as standardsubstance and tetrahydrofuran as elution solvent.

Other Components:

Thermal Crosslinking Accelerator

In the present invention, a thermal crosslinking accelerator may beblended to the composition for forming a silicon-containing resistunderlayer film. As to the blendable thermal crosslinking accelerator,compounds shown by the following general formula (5) or (6) may bementioned. Specifically, the materials described in Japanese PatentLaid-Open (kokai) No. 2007-302873 may be mentioned,L_(a)H_(b)X  (5)

wherein, L represents lithium, sodium, potassium, rubidium, or cesium; Xrepresents a hydroxyl group, or a monovalent, or a divalent or higherorganic acid group having 1 to 30 carbon atoms; “a” represents aninteger of 1 or more, “b” represents 0 or an integer of 1 or more, anda+b represents a valency of the hydroxyl group or the organic acidgroup,MY  (6)

wherein, M represents sulfonium, iodonium, or ammonium; and Y representsa non-nucleophilic counter ion.

Note that the thermal crosslinking accelerators can be used solely inone kind or combinedly in two or more kinds. The addition amount of thethermal crosslinking accelerators is preferably 0.01 to 50 parts bymass, and more preferably 0.1 to 40 parts by mass, relative to 100 partsby mass of the base polymer (i.e., the silicon-containing compounds ofthe component (A) and (B) obtained by the above procedure).

(Organic Acid)

To improve stability of the silicon-containing resist under layerfilm-forming composition to be used for the present invention, it ispreferably to add a monovalent, divalent, or higher organic acid having1 to 30 carbon atoms. Examples of the acid to be added include formicacid, acetic acid, propionic acid, butanoic acid, pentanoic acid,hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoicacid, oleic acid, stearic acid, linoleic acid, linolenic acid, benzoicacid, phthalic acid, isophthalic acid, terephthalic acid, salicylicacid, trifluoroacetic acid, monochloroacetic acid, dichloroacetic acid,trichloroacetic acid, oxalic acid, malonic acid, methylmalonic acid,ethylmalonic acid, propylmalonic acid, butylmalonic acid,dimethylmalonic acid, diethylmalonic acid, succinic acid, methylsuccinicacid, glutaric acid, adipic acid, itaconic acid, maleic acid, fumaricacid, citraconic acid, and citric acid. Particularly preferable examplesinclude oxalic acid, maleic acid, formic acid, acetic acid, propionicacid, and citric acid. It is possible to mixingly use two or more kindsof acids, so as to keep the stability. The addition amount is 0.001 to25 parts by mass, preferably 0.01 to 15 parts by mass, and morepreferably 0.1 to 5 parts by mass, relative to 100 parts by mass of thesilicon contained in the composition.

Alternatively, the organic acid is preferably blended in a manner toachieve 0≦pH≦7, more preferably 0.3≦pH≦6.5, and even more preferably0.5≦pH≦6, when evaluated as a pH of the composition.

(Water)

In the present invention, into the composition may be added water. Whenwater is added thereinto, the silicon-containing compound is hydrated,so that a lithography performance may be improved. Amount of water inthe solvent component of the composition is in the range of more than 0%by mass to less than 50% by mass, more preferably 0.3 to 30% by mass, orstill more preferably 0.5 to 20% by mass. If amount of each component istoo large, uniformity of a silicon-containing resist underlayer filmbecomes poor, whereby eye holes occur if the worst happens. On the otherhand, if the amount thereof is too small, a lithography performance isdeteriorated; and thus it is not desirable.

Amount of totality of the solvent including water is preferably 100 to100,000 parts by mass, or in particular 200 to 50,000 parts by mass,relative to 100 parts by mass of the base polymer of the component (A)and (B).

(Photoacid Generator)

Into the composition of the present invention, a photoacid generator maybe added. Concrete examples of photoacid generators to be used for thepresent invention include a material described in paragraphs (0160) to(0179) of Japanese Patent Laid-Open (kokai) No. 2009-126940.

(Stabilizer)

Further, into the composition of the present invention, a stabilizer maybe added. As a stabilizer, a monovalent or divalent or higher alcoholhaving a cyclic ether as a substitutional group may be added thereinto.In particular, when the material(s) described in paragraphs (0180) to(0184) of Japanese Patent Laid-Open (kokai) No. 2009-126940 is added, sothat the composition for forming a silicon-containing resist underlayerfilm can be improved in stability.

(Surfactant)

Furthermore, in the present invention, it is possible to blend thecomposition with a surfactant, as required. Concrete examples of such asurfactant include materials described in paragraph (0185) of JapanesePatent Laid-Open (kokai) No. 2009-126940.

[Negative-Patterning Process]

(Negative-Patterning Process 1)

The present invention provides a patterning process, wherein an organicunderlayer film is formed on a body to be processed by using anapplication-type composition for the organic underlayer film, on thisorganic underlayer film is formed a silicon-containing resist underlayerfilm by using the composition for forming the silicon-containing resistunderlayer film, on this silicon-containing resist underlayer film isformed a photoresist film by using a chemically amplified resistcomposition, the photoresist film is exposed to a high energy beam afterheat treatment, a negative pattern is formed by dissolving an unexposedarea of the photoresist film by using an organic solvent developer,pattern transfer is made onto the silicon-containing resist underlayerfilm by dry-etching by using the photoresist film having the negativepattern as a mask, pattern transfer is made onto the organic underlayerfilm by dry-etching by using the silicon-containing resist underlayerfilm having the transferred pattern as a mask, and then pattern transferis made onto the body to be processed by dry-etching by using theorganic underlayer film having the transferred pattern as a mask (whatis called “multilayer resist method”).

(Negative-Patterning Process 2)

In addition, the present invention provides a patterning process,wherein an organic hard mask mainly comprising carbon is formed on abody to be processed by a CVD method, on this organic hard mask isformed a silicon-containing resist underlayer film by using thecomposition for forming the silicon-containing resist underlayer film,on this silicon-containing resist underlayer film is formed aphotoresist film by using a chemically amplified resist composition, thephotoresist film is exposed to a high energy beam after heat treatment,a negative pattern is formed by dissolving an unexposed area of thephotoresist film by using an organic solvent developer, pattern transferis made onto the silicon-containing resist underlayer film bydry-etching by using the photoresist film having the negative pattern asa mask, pattern transfer is made onto the organic hard mask bydry-etching by using the silicon-containing resist underlayer filmhaving the transferred pattern as a mask, and then pattern transfer ismade onto the body to be processed by dry-etching by using the organichard mask having the transferred pattern as a mask (what is called“multilayer resist method”).

When a negative pattern is formed by using the composition of thepresent invention for a resist underlayer film, by optimizingcombination with the CVD film or the organic underlayer film in the wayas mentioned above, a pattern formed with a photoresist can be formed ona substrate without causing size difference.

Further, in photo-exposure of the photoresist film, the contact angle ofa part of the silicon-containing resist underlayer film corresponding toan exposed area of the exposed photoresist film is decreased by 10degrees or more after photo-exposure as compared with beforephoto-exposure.

When the contact angle of the of the part of the silicon-containingresist underlayer film corresponding to the exposed area of the exposedphotoresist film is decreased by 10 degrees or more as compared withbefore the photo-exposure, difference of the contact angle with that ofthe resist pattern after the negative development becomes smallerthereby enhancing adhesion properties and thus prohibiting pattern fall;and as a result, a fine pattern may be formed.

The silicon-containing resist underlayer film used in the patterningprocess of the present invention can be formed on a body to be processedby spin coating and so on of the composition for forming thesilicon-containing resist underlayer film of the present invention,similarly to the method used for the photoresist film. After spincoating, it is preferable that the solvent is evaporated, and then, inorder to avoid mixing with the photoresist film, baking is carried outso as to accelerate a crosslinking reaction. Baking temperature ispreferably in the range of 50 to 500° C., and with the time thereofbeing preferably in the range of 10 to 300 seconds. Especiallypreferable temperature range thereof is 400° C. or lower to reducethermal damage to a device, though depending on structure of the deviceto be produced.

Usable as the body to be processed is a substrate for a semiconductordevice, or the substrate for a semiconductor device coated with a metalfilm, metal carbide film, metal oxide film, metal nitride film, or metaloxide nitride film, as a layer to be processed (process-targetedportion).

Although a silicon substrate is typically used as the substrate for asemiconductor device, without limited thereto, it is possible to use asubstrate made of a material such as Si, amorphous silicon (a-Si), p-Si,SiO₂, SiN, SiON, W, TiN, Al, or the like, which can be different fromthat of the layer to be processed.

Usable as a metal constituting the body to be processed is silicon,titanium, tungsten, hafnium, zirconium, chromium, germanium, copper,aluminum, iron, or an alloy thereof, and usable as the layer to beprocessed containing such a metal is Si, SiO₂, SiN, SiON, SiOC, p-Si,α-Si, TiN, WSi, BPSG, SOG, Cr, CrO, CrON, MoSi, W, W—Si, Al, Cu, Al—Si,or the like, or various low dielectric films, or an etching stopper filmtherefor, for example, which can each be formed to typically have athickness of 50 to 10,000 nm, and particularly 100 to 5,000 nm.

In the negative-patterning process of the present invention, thephotoresist film is of a chemical amplification type, and is notparticularly restricted as far as it can form a negative pattern bydevelopment using an organic solvent developer.

For example, if the exposure step of the present invention is carriedout by an exposure process using an ArF excimer laser beam, any resistcomposition used for a usual ArF excimer laser beam may be used as forthe photoresist film.

Already known as such a resist composition for ArF excimer laser arenumerous candidates including known resins, which are generallyclassified into poly(meth)acryl resins, COMA (Cyclo Olefin MaleicAnhydride) resins, COMA-(meth)acryl hybrid resins, ROMP (Ring OpeningMethathesis Polymerization) resins, polynorbornene resins, and the like;and resist compositions using poly(meth)acryl resins among them aresuperior to other type resins in terms of resolution performance becausethe poly(meth)acryl resins each have an alicyclic structure introducedin its side-chain to thereby ensure an etching resistance.

In the negative-patterning process, after the silicon-containing resistunderlayer film is formed, the photoresist film is formed thereon byusing a photoresist composition solution by using preferably a spincoating method, similarly to the case of the silicon-containing resistunderlayer film. After the photoresist composition is applied by a spincoating method, pre-baking is carried out, preferably at 80 to 180° C.and for 10 to 300 seconds. Then, this is followed by exposure, and then,the organic solvent development to obtain a negative resist pattern. Inaddition, it is preferable that post-exposure baking (PEE) is carriedout after the exposure.

As the developer of the organic solvent, it is possible to use thedeveloper containing, as a component(s), one or more kinds selected fromamong: 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone,2-hexanone, 3-hexanone, diisobutylketone, methylcyclohexanone,acetophenone, methylacetophenone, propyl acetate, butyl acetate,isobutyl acetate, amyl acetate, butenyl acetate, isoamyl acetate, phenylacetate, propyl formate, butyl formate, isobutyl formate, amyl formate,isoamyl formate, methyl valerate, methyl pentenoate, methyl crotonate,ethyl crotonate, methyl lactate, ethyl lactate, propyl lactate, butyllactate, isobutyl lactate, amyl lactate, isoamyl lactate, methyl2-hydroxy-isobutyrate, ethyl 2-hydroxy-isobutyrate, methyl benzoate,ethyl benzoate, phenyl acetate, benzyl acetate, methyl phenylacetate,benzyl formate, phenylethyl formate, methyl 3-phenylpropionate, benzylpropionate, ethyl phenylacetate, and acetic acid 2-phenylethyl, it ispreferable to use the developer containing one kind, or two or morekinds of the aforementioned developer components, in a total amount of50% or more by mass, from standpoints of improving pattern collapse, forexample.

In the patterning process of the present invention, when thesilicon-containing resist underlayer film is etched, the etching iscarried out by using a gas mainly comprising a fluorine-containing gassuch as a freon gas. In order to reduce film loss of the photoresistfilm, it is preferable that the silicon-containing film have a highetching speed to the foregoing gas.

In the multi-layer resist method as mentioned above, in the case that anorganic underlayer film is formed between the silicon-containing resistunderlayer film and the body to be processed whereby this organicunderlayer film is used as an etching mask for the body to be processed,the organic underlayer film is preferably an organic film having anaromatic skeleton; however, in the case that the organic underlayer filmis a sacrificial film or the like, a silicon-containing organicunderlayer film may be used provided that the silicon amount containedtherein is 15% or less by mass.

As to the material for an organic underlayer film like this, usable arematerials such as those heretofore known as the composition for theresist underlayer film in a bilayer resist method or a three-layerresist method including heretofore known compositions for the underlayerfilm in a three-layer resist method or in a bilayer resist method usinga silicon resist composition, and also many resins including a novolakresin such as 4,4′-(9-fluorenylidene)bisphenol novolak resin (molecularweight of 11,000) described in Japanese Patent Laid-Open (kokai) No.2005-128509. In the case that a higher heat resistance than a usualnovolak is wanted, a polycyclic skeleton may be introduced such as forexample in the case of 6,6′-(9-fluorenylidene)-di(2-naphthol) novolakresin, or in addition, a polyimide resin may be selected (for example,Japanese Patent Laid-Open (kokai) No. 2004-153125).

The organic underlayer film can be formed on the body to be processed byusing a composition solution in the same manner as the photoresistcomposition, such as by spin coating. After forming the organicunderlayer film by spin coating or the like, it is desirable to bake itto evaporate an organic solvent therefrom. Baking is to be preferablyconducted within a temperature range of BO to 300° C. and within a timerange of 10 to 300 seconds.

Note that the thickness of the organic underlayer film is 5 nm or more,particularly preferably 20 nm or more to 50,000 nm or less withoutparticularly limited thereto though the thickness varies depending onthe etching condition; the thickness of the silicon-containing resistunderlayer film of the present invention is to be 1 nm or more to 500 nmor less, preferably to be 300 nm or less, more preferably to be 200 nmor less; and the thickness of a photoresist film is preferably between 1nm or more and 200 nm or less.

[Patterning Process of the Present Invention According to theThree-Layer Resist Method]

The negative-patterning process of the present invention according tothe three-layer resist method as mentioned above is done as following(refer to FIG. 1). In this process, firstly the organic underlayer film2 is formed on the body to be processed 1 by a spin coating method (FIG.1 (I-A)). It is desired that the organic under layer film 2 have highetching resistance because this acts as a mask during etching of thebody to be processed 1; and it is also desired that this undergocrosslinking by heat or an acid after forming by spin coating becausemixing with the silicon-containing film of the upper layer isundesirable.

Then, onto it the silicon-containing resist under layer film 3 is formedby a spin coating method by using the composition of the presentinvention for a silicon-containing resist underlayer film (FIG. 1(I-B)), and then the photoresist film 4 is formed thereonto by a spincoating method (FIG. 1 (I-C)). Meanwhile, the silicon-containing resistunderlayer film 3 can be formed by using a composition giving thesilicon-containing resist underlayer film 3 whose pure-water contactangle in the part corresponding to the exposed area of the photoresistfilm 4 is in the range of 40 degrees or more to lower than 70 degreesafter exposure.

The photoresist film 4 is subjected to a usual pattern exposure, byusing the mask 5, using a light source P corresponding to thephotoresist film 4, such as, for example, a KrF excimer laser beam, anArF excimer laser beam, an F₂ laser beam, and an EUV beam, to form apattern preferably by any of a photolithography with the wavelengthranging from 10 nm or more to 300 nm or less, a direct drawing by anelectron beam, and a nanoimprinting, or a combination of them (FIG. 1(I-D)); and thereafter, heat treatment thereof under the conditionmatching with each photoresist film (FIG. 1 (I-E)), development by theorganic solvent development (negative development), and then, asappropriate, rinsing are performed to obtain the negative resist pattern4 a (FIG. 1 (I-F)).

Then, by using this negative resist pattern 4 a as an etching mask,etching is carried out under the dry etching condition that the etchingspeed of the silicon-containing resist underlayer film 3 issignificantly faster relative to the photoresist film, for example, bydry etching using a fluorine-based gas plasma. As a result, thesilicon-containing resist underlayer film pattern of negative type 3 acan be obtained without substantially receiving an effect of patternchange due to side etching of the resist film (FIG. 1 (I-G)).

Then, the organic underlayer film 2 is dry-etched under the dry etchingcondition that the etching speed of the organic resist underlayer filmis significantly faster relative to the substrate having thesilicon-containing resist underlayer film pattern of negative type 3 ahaving the transferred negative resist pattern 4 a obtained above, forexample, by a reactive dry etching with a gas plasma containing oxygenor by a reactive dry etching with a gas plasma containing hydrogen andnitrogen. In this etching process, the organic underlayer film patternof negative type 2 a is obtained, while at the same time, the uppermostphotoresist film is usually lost (FIG. 1 (I-H)). Then, by using theorganic underlayer film pattern of negative type 2 a thereby obtained asan etching mask, the body to be processed 1 can be dry-etched with highprecision by using, for example, a fluorine-based dry etching or achlorine-based dry etching to transfer the negative pattern 1 a to thebody to be processed 1 (FIG. 1 (I-I)).

Meanwhile, in the process of the three-layer resist method mentionedabove, an organic hard mask formed by a CVD method may also be usedinstead of the organic underlayer film 2. In this case also, the body tobe processed can be processed by the procedure similar to the aboveprocedure.

[Positive-Patterning Process]

(Positive-Patterning Process 1)

In addition, the present invention provides a patterning process,wherein an organic underlayer film is formed on a body to be processedby using an application-type composition for the organic underlayerfilm, on this organic underlayer film is formed a silicon-containingresist underlayer film by using the composition for forming thesilicon-containing resist underlayer film, on this silicon-containingresist underlayer film is formed a photoresist film by using achemically amplified resist composition, the photoresist film is exposedto a high energy beam after heat treatment, a positive pattern is formedby dissolving an exposed area of the photoresist film by using analkaline developer, pattern transfer is made onto the silicon-containingresist underlayer film by dry-etching by using the photoresist filmhaving the positive pattern as a mask, pattern transfer is made onto theorganic underlayer film by dry-etching by using the silicon-containingresist underlayer film having the transferred pattern as a mask, andthen pattern transfer is made onto the body to be processed bydry-etching by using the organic underlayer film having the transferredpattern as a mask.

(Positive-Patterning Process 2)

Further, a patterning process, wherein an organic hard mask mainlycomprising carbon is formed on a body to be processed by a CVD method,on this organic hard mask is formed a silicon-containing resistunderlayer film by using the composition for forming thesilicon-containing resist underlayer film, on this silicon-containingresist underlayer film is formed a photoresist film by using achemically amplified resist composition, the photoresist film is exposedto a high energy beam after heat treatment, a positive pattern is formedby dissolving an exposed area of the photoresist film by using analkaline developer, pattern transfer is made onto the silicon-containingresist underlayer film by dry-etching by using the photoresist filmhaving the positive pattern as a mask, pattern transfer is made onto theorganic hard mask by dry-etching by using the silicon-containing resistunderlayer film having the transferred pattern as a mask, and thenpattern transfer is made onto the body to be processed by dry-etching byusing the organic hard mask having the transferred pattern as a mask.

When patterning is done by a positive development using the compositionof the present invention for forming a resist underlayer film, byoptimizing combination with the CVD film or the organic underlayer filmin the way as mentioned above, a pattern formed with a photoresist canbe formed on a substrate without causing size difference.

In photo-exposure of the photoresist film, it is preferable that changeof the contact angle in a part of the silicon-containing resistunderlayer film corresponding to an unexposed area of the exposedphotoresist film is 10 degree or less as compared with beforephoto-exposure. If difference of the contact angles between an unexposedarea of the photoresist film and a part of the silicon-containing resistunderlayer film corresponding to this area is 10 degrees or less, goodadhesion can be realized in the positive development; and as a result, afine pattern can be formed.

In the positive patterning process of the present invention, thephotoresist film is not particularly restricted provided that the filmis of a chemically amplifying type and a positive pattern can be formedby development using an alkaline developer. As to other items includingmethod for film formation, body to be processed, organic underlayerfilm, and organic hard mask may be the same as those explained in thenegative patterning process.

In the positive patterning process, after formation of the photoresistfilm and heat treatment, photo-exposure is done, and then an alkalinedevelopment is done by using an alkaline developer to obtain a positiveresist pattern. In addition, it is preferable to carry out post-exposurebake (PEB) after the photo-exposure.

As the alkaline developer, tetramethylammonium hydroxide (TMAH) etc. canbe used.

[Patterning Process of the Present Invention According to theThree-Layer Resist Method]

The positive-patterning process of the present invention according tothe three-layer resist method as mentioned above is done as following(refer to FIG. 1).

In this process, firstly the organic underlayer film 2 is formed on thebody to be processed 1 by a spin coating method (FIG. 1 (II-A)). It isdesired that the organic underlayer film 2 has high etching resistancebecause this acts as a mask during etching of the body to be processed1; and it is also desired that this undergoes crosslinking by heat or anacid after forming by spin coating because mixing with thesilicon-containing resist underlayer film of the upper layer isundesirable.

Then, onto it the silicon-containing resist underlayer film 3 is formedby a spin coating method by using the composition of the presentinvention for forming a silicon-containing resist underlayer film (FIG.1 (II-B)), and then the photoresist film 4 is formed thereonto by a spincoating method (FIG. 1 (II-C)). Meanwhile, the silicon-containing resistunderlayer film 3 can be formed by using a composition giving thesilicon-containing resist underlayer film 3 whose pure-water contactangle in the part corresponding to the exposed area of the photoresistfilm 4 is in the range of 40 degrees or more to lower than 70 degreesafter exposure.

The photoresist film 4 is subjected to a usual pattern exposure using alight source P corresponding to the photoresist film 4, such as, forexample, a KrF excimer laser beam, an ArF excimer laser beam, an F₂laser beam, and an EUV beam, to form a pattern preferably by any of aphotolithography with the wavelength ranging from 10 nm or more to 300nm or less, a direct drawing by an electron beam, and a nanoimprinting,or a combination of them (FIG. 1 (II-D)); and thereafter, heat treatmentthereof under the condition matching with each photoresist film (FIG. 1(II-E)), development by the alkaline developer, and then, asappropriate, rinsing are performed to obtain the positive resist pattern4 b (FIG. 1 (II-F)).

Then, by using this negative resist pattern 4 b as an etching mask,etching is carried out under the dry etching condition that the etchingspeed of the silicon-containing resist underlayer film 3 issignificantly faster relative to the photoresist film, for example, bydry etching using a fluorine-based gas plasma. As a result, thesilicon-containing resist underlayer film pattern of positive type 3 bcan be obtained without substantially receiving an effect of patternchange due to side etching of the resist film (FIG. 1 (II-G)).

Then, the organic underlayer film 2 is dry-etched under the dry etchingcondition that the etching speed of the organic resist underlayer film 2is significantly faster relative to the substrate having thesilicon-containing resist underlayer film pattern 3 b having thetransferred positive resist pattern obtained above, for example, by areactive dry etching with a gas plasma containing oxygen or by areactive dry etching with a gas plasma containing hydrogen and nitrogen.In this etching process, the organic under layer film pattern ofpositive type 2 b is obtained, while at the same time, the uppermostphotoresist film is usually lost (FIG. 1 (II-H)). Then, by using theorganic underlayer film pattern of positive type 2 b thereby obtained asan etching mask, the body to be processed 1 can be dry-etched with highprecision by using, for example, a fluorine-based dry etching or achlorine-based dry etching to transfer the positive pattern 1 b to thebody to be processed 1 (FIG. 1 (II-I)).

Meanwhile, in the process of the three-layer resist method mentionedabove, an organic hard mask formed by a CVD method may also be usedinstead of the organic underlayer film 2. In this case also, the body tobe processed 1 can be processed by the procedure similar to the aboveprocedure.

EXAMPLES

Although Synthesis examples, Examples, and Comparative examples will beshown and the present invention will be explained in detail hereafter,the present invention is not restricted to the following Examples. Notethat the symbol “%” in the Examples represents a mass %, and themolecular weight measurement was based on GPC.

Synthesis of the Component (A) Synthesis Example A-1

Into a mixture of 120 g of methanol, 1 g of methansulfonic acid, and 60g of deionized water was added a mixture of 33.8 g of 4-t-butoxyphenyltrimethoxy silane (Monomer-120), 17.0 g of methyl trimethoxy silane(Monomer-101), and 47.0 g of triisopropyl borate (Monomer-110); andthen, the hydrolysis-condensation reaction was carried out at 40° C. for12 hours. After the reaction, 100 g of propylene glycol ethyl ether(PGEE) was added into it, and then, by-produced alcohols were removed bydistillation under reduced pressure. Into it were added 1000 mL of ethylacetate and 300 g of PGEE to separate an aqueous layer. Into an organiclayer remained was added 100 mL of ion-exchange water; and then, theresulting mixture was agitated, settled, and separated into the layers.This procedure was repeated for three times. The organic layer remainedwas concentrated under reduced pressure to obtain 300 g of PGEE solutionof the silicon-containing compound A-1 (polymer concentration of 15%).By an ion chromatography analysis of the obtained solution, amethanesulfonate ion was not detected. The polystyrene-equivalentmolecular weight (Mw) of this compound was 3,700.

By using the monomers shown in Table 1, Synthesis Examples A-2 to A-20and Synthesis Examples A-24 to A-25 were carried out under theconditions similar to those of Synthesis Example A-1 to obtainrespective intended products. Meanwhile, in Synthesis Examples A-24 andA-25, a constituting unit derived from the general formula (2) is notcontained; and thus, they are not the component (A) of the compositionof the present invention.

Synthesis Example A-21

Into a mixture of 240 g of ethanol, 6 g of 25% tetramethylammoniumhydroxide, and 120 g of deionized water was added a mixture of 67.6 g of4-t-butoxyphenyl trimethoxy silane (Monomer-120), 17.0 g of methyltrimethoxy silane (Monomer-101), 5.0 g of phenyl trimethoxy silane(Monomer-100), and 18.8 g of triisopropyl borate (Monomer-110); andthen, the hydrolysis-condensation reaction was carried out at 40° C. for4 hours. After the reaction, 10 g of acetic acid was added into it forneutralization, and then, by-produced alcohols were removed bydistillation under reduced pressure. Into it were added 1000 mL of ethylacetate and 300 g of PGEE to separate an aqueous layer. Into an organiclayer remained was added 100 mL of ion-exchange water; and then, theresulting mixture was agitated, settled, and separated into the layers.This procedure was repeated for three times. The organic layer remainedwas concentrated under reduced pressure to obtain 300 g of PGEE solutionof the silicon-containing compound A-21 (polymer concentration of 15%).The polystyrene-equivalent molecular weight (Mw) of this compound was9,700.

By using the monomers shown in Table 1, Synthesis Examples A-22 to A-23were carried out under the conditions similar to those of SynthesisExample A-21 to obtain respective intended products.

TABLE 1 Synthesis Example Raw material for reaction Mw A-1 Monomer-101:17.0 g, Monomer-110: 47.0 g, 3700 Monomer-120: 33.8 g A-2 Monomer-101:17.0 g, Monomer-111: 85.1 g, 3100 Monomer-120: 33.8 g A-3 Monomer-101:17.0 g, Monomer-112: 91.3 g, 2300 Monomer-120: 33.8 g A-4 Monomer-101:17.0 g, Monomer-113: 71.0 g, 2500 Monomer-121: 35.6 g A-5 Monomer-101:17.0 g, Monomer-114: 81.1 g, 2100 Monomer-121: 35.6 g A-6 Monomer-100:5.0 g, Monomer-101: 6.8 g, 3000 Monomer-102: 22.8 g, Monomer-110: 18.8g, Monomer-122: 57.1 g A-7 Monomer-100: 5.0 g, Monomer-101: 6.8 g, 2400Monomer-102: 22.8 g, Monomer-111: 34.0 g, Monomer-122: 57.1 g A-8Monomer-100: 5.0 g, Monomer-101: 6.8 g, 2300 Monomer-102: 22.8 g,Monomer-112: 36.5 g, Monomer-122: 57.1 g A-9 Monomer-100: 5.0 g,Monomer-101: 6.8 g, 2900 Monomer-103: 31.3 g, Monomer-113: 28.4 g,Monomer-123: 55.4 g A-10 Monomer-100: 5.0 g, Monomer-101: 6.8 g, 3700Monomer-102: 22.8 g, Monomer-114: 32.4 g, Monomer-123: 55.4 g A-11Monomer-101: 13.6 g, Monomer-110: 28.2 g, 3300 Monomer-124: 74.6 g A-12Monomer-101: 13.6 g, Monomer-111: 51.1 g, 2200 Monomer-124: 74.6 g A-13Monomer-101: 13.6 g, Monomer-112: 54.8 g, 3200 Monomer-124: 74.6 g A-14Monomer-100: 29.7 g, Monomer-101: 6.8 g, 3700 Monomer-113: 14.2 g,Monomer-127: 82.6 g A-15 Monomer-100: 29.7 g, Monomer-101: 6.8 g, 3500Monomer-114: 16.2 g, Monomer-127: 82.6 g A-16 Monomer-101: 23.8 g,Monomer-110: 37.6 g, 2500 Monomer-126: 44.6 g A-17 Monomer-101: 23.8 g,Monomer-111: 68.1 g, 2800 Monomer-127: 44.6 g A-18 Monomer-101: 23.8 g,Monomer-114: 73.0 g, 3600 Monomer-127: 44.6 g A-19 Monomer-101: 23.8 g,Monomer-110: 37.6 g, 2800 Monomer-128: 39.1 g A-20 Monomer-101: 23.8 g,Monomer-110: 37.6 g, 3500 Monomer-129: 33.8 g A-21 Monomer-100: 5.0 g,Monomer-101: 17.0 g, 9700 Monomer-110: 18.8 g, Monomer-120: 67.6 g A-22Monomer-101: 20.4 g, Monomer-113: 14.2 g, 7200 Monomer-125: 95.5 g A-23Monomer-101: 20.4 g, Monomer-114: 16.2 g, 9600 Monomer-125: 95.5 g A-24Monomer-101: 17.0 g, Monomer-102: 38.1 g, 3700 Monomer-120: 33.8 g A-25Monomer-101: 34.1 g, Monomer-105: 82.6 g 3600PhSi(OCH₃)₃ [Monomer-100] CH₃Si(OCH₃)₃ [Monomer-101] Si(OCH₃)₄[Monomer-102] Si(OC₂H₅)₄ [Monomer-103]

B(OC₃H₇)₃ [Monomer-110] Ti(OC₄H₉)₄ [Monomer-111] Ge(OC₄H₉)₄[Monomer-112] P₂O₅ [Monomer-113] Al[CH₃COCH═C(O—)CH₃]₃ [Monomer-114]

Synthesis of the Component (B) Synthesis Example B-1

Into a mixture of 120 g of methanol, 1 g of 70% nitric acid, and 60 g ofdeionized water was added a mixture of 5.0 g of phenyl trimethoxy silane(Monomer-100), 3.4 g of methyl trimethoxy silane (Monomer-101), and 68.5g of tetramethoxy silane (Monomer-102); and then, thehydrolysis-condensation reaction was carried out at 40° C. for 12 hours.After the reaction, 300 g of PGEE was added into it, and then,by-produced alcohols and excess water were removed by distillation underreduced pressure to obtain 300 g of PGEE solution of thesilicon-containing compound B-1 (polymer concentration of 10%). By anion chromatography analysis of the obtained solution, a nitrate ion wasnot detected. The polystyrene-equivalent molecular weight (Mw) of thiscompound was 2,400.

By using the monomers shown in Table 2, Synthesis Examples B-2 to B-8were carried out under the conditions similar to those of SynthesisExample B-1 to obtain respective intended products. Meanwhile, as to B-4and B-8, amount of the constituting unit derived from the generalformula (4) is 40% by mole in the component (B).

TABLE 2 Synthesis Example Raw material for reaction Mw B-1 Monomer-100:5.0 g, Monomer-101: 3.4 g, 2400 Monomer-102: 68.5 g B-2 Monomer-105: 5.7g, Monomer-101: 10.2 g, 2800 Monomer-102: 60.9 g B-3 Monomer-100: 5.0 g,Monomer-101: 30.6 g, 1700 Monomer-102: 38.1 g B-4 Monomer-100: 5.0 g,Monomer-101: 37.5 g, 2300 Monomer-102: 30.4 g B-5 Monomer-100: 5.0 g,Monomer-101: 3.4 g, 1900 Monomer-103: 94.0 g B-6 Monomer-104: 5.3 g,Monomer-101: 10.2 g, 3300 Monomer-103: 83.5 g B-7 Monomer-100: 5.0 g,Monomer-101: 30.6 g, 2600 Monomer-103: 52.2 g B-8 Monomer-100: 5.0 g,Monomer-101: 37.5 g, 3000 Monomer-103: 41.8 g

Examples and Comparative Examples

Each of the silicon-containing compounds (A-1) to (A-25) obtained in theforegoing synthesis examples as the component (A), each of thesilicon-containing compounds (B-1) to (B-8) obtained in the foregoingsynthesis examples as the component (B), a thermal crosslinkingaccelerator, a photoacid generator, an acid, a solvent, and water weremixed with the respective ratios shown in Table 3; and then, theresulting mixture was filtrated through a 0.1-μm filter made of afluorinated resin to obtain respective composition solutions Sol.1 toSol.44 for forming a silicon-containing resist underlayer film.Meanwhile, Sol.1 to Sol.42 are used for Examples of the presentinvention, and Sol.43 and Sol.44, not containing the component (A) ofthe present invention, are used for Comparative Examples. Further,Film-43 and Film-44 prepared from Sol.43 and Sol.44 are shown inComparative Examples.

TABLE 3 Silicon- Silicon- containing containing Thermal compound:compound: crosslinking Photoacid Water Component A Component Baccelerator generator Acid Solvent (parts (parts by (parts by (parts by(parts by (parts (parts by No. mass) mass) mass) mass) by mass) by mass)mass) Sol. 1 A-1(0.1) B-1(3.9) TPSOH — maleic PGEE water (0.04) acid(150) (15) (0.04) Sol. 2 A-1(0.1) B-1(3.9) TPSHCO₃ — oxalic PGEE water(0.04) acid (150) (15) (0.04) Sol. 3 A-1(0.1) B-1(3.9) TPSOx — maleicPGEE water (0.04) acid (150) (15) (0.04) Sol. 4 A-1(0.1) B-1(3.9) TPSTFA— maleic PGEE water (0.04) acid (150) (15) (0.04) Sol. 5 A-1(0.1)B-1(3.9) TPSOCOPh — oxalic PGEE water (0.04) acid (150) (15) (0.04) Sol.6 A-1(0.1) B-1(3.9) TPSH₂PO₄ — oxalic PGEE water (0.04) acid (150) (15)(0.04) Sol. 7 A-1(0.1) B-1(3.9) QMAMA — maleic PGEE water (0.04) acid(150) (15) (0.04) Sol. 8 A-1(0.1) B-1(3.9) QBANO₃ — maleic PGEE water(0.04) acid (150) (15) (0.04) Sol. 9 A-1(0.1) B-1(3.9) QMATFA TPSNfmaleic PGEE water (0.04) (0.04) acid (150) (15) (0.04) Sol. 10 A-1(0.1)B-1(3.9) Ph₂ICl — maleic PGEE water (0.04) acid (150) (15) (0.04) Sol.11 A-1(0.1) B-1(3.9) TPSMA — maleic PGEE water (0.04) acid (150) (15)(0.04) Sol. 12 A-2(0.1) B-1(3.9) TPSMA — oxalic PGEE water (0.04) acid(150) (15) (0.04) Sol. 13 A-3(0.1) B-1(3.9) TPSMA — maleic PGEE water(0.04) acid (150) (15) (0.04) Sol. 14 A-4(0.1) B-1(3.9) TPSMA — maleicPGEE water (0.04) acid (150) (15) (0.04) Sol. 15 A-5(0.1) B-1(3.9) TPSMA— oxalic PGEE water (0.04) acid (150) (15) (0.04) Sol. 16 A-6(0.1)B-1(3.9) TPSMA — oxalic PGEE water (0.04) acid (150) (15) (0.04) Sol. 17A-7(0.1) B-1(3.9) TPSMA — maleic PGEE water (0.04) acid (150) (15)(0.04) Sol. 18 A-8(0.1) B-1(3.9) TPSMA — maleic PGEE water (0.04) acid(150) (15) (0.04) Sol. 19 A-9(0.1) B-1(3.9) TPSMA — maleic PGEE water(0.04) acid (150) (15) (0.04) Sol. 20 A-10(0.1) B-1(3.9) TPSMA TPSNfmaleic PGEE water (0.04) (0.04) acid (150) (15) (0.04) Sol. 21 A-11(0.1)B-1(3.9) TPSMA — maleic PGEE water (0.04) acid (150) (15) (0.04) Sol. 22A-12(0.1) B-1(3.9) TPSMA — maleic PGEE water (0.04) acid (150) (15)(0.04) Sol. 23 A-13(0.1) B-1(3.9) TPSMA — maleic PGEE water (0.04) acid(150) (15) (0.04) Sol. 24 A-14(0.1) B-1(3.9) TPSMA — maleic PGEE water(0.04) acid (150) (15) (0.04) Sol. 25 A-15(0.1) B-1(3.9) TPSMA — maleicPGEE water (0.04) acid (150) (15) (0.04) Sol. 26 A-16(0.1) B-1(3.9)TPSMA — maleic PGEE water (0.04) acid (150) (15) (0.04) Sol. 27A-17(0.1) B-1(3.9) TPSMA — maleic PGEE water (0.04) acid (150) (15)(0.04) Sol. 28 A-18(0.1) B-1(3.9) TPSMA — maleic PGEE water (0.04) acid(150) (15) (0.04) Sol. 29 A-19(0.1) B-1(3.9) TPSMA — maleic PGEE water(0.04) acid (150) (15) (0.04) Sol. 30 A-20(0.1) B-1(3.9) TPSMA TPSNfmaleic PGEE water (0.04) (0.04) acid (150) (15) (0.04) Sol. 31 A-21(0.1)B-1(3.9) TPSMA — maleic PGEE water (0.04) acid (150) (15) (0.04) Sol. 32A-22(0.1) B-1(3.9) TPSMA — maleic PGEE water (0.04) acid (150) (15)(0.04) Sol. 33 A-23(0.1) B-1(3.9) TPSMA — maleic PGEE water (0.04) acid(150) (15) (0.04) Sol. 34 A-1(0.1) B-2(3.9) TPSMA — maleic PGEE water(0.04) acid (150) (15) (0.04) Sol. 35 A-1(0.1) B-3(3.9) TPSMA — maleicPGEE water (0.04) acid (150) (15) (0.04) Sol. 36 A-1(0.1) B-5(3.9) TPSMA— maleic PGEE water (0.04) acid (150) (15) (0.04) Sol. 37 A-1(0.1)B-6(3.9) TPSMA — maleic PGEE water (0.04) acid (150) (15) (0.04) Sol. 38A-1(0.1) B-7(3.9) TPSMA — maleic PGEE water (0.04) acid (150) (15)(0.04) Sol. 39 A-1(1.5) B-1(2.5) TPSMA — maleic PGEE water (0.04) acid(150) (15) (0.04) Sol. 40 A-1(2.0) B-1(2.0) TPSMA — maleic PGEE water(0.04) acid (150) (15) (0.04) Sol. 41 A-1(0.1) B-4(3.9) TPSMA — maleicPGEE water (0.04) acid (150) (15) (0.04) Sol. 42 A-1(0.1) B-8(3.9) TPSMA— maleic PGEE water (0.04) acid (150) (15) (0.04) Sol. 43 A-24(0.1)B-1(3.9) TPSMA — maleic PGEE water (0.04) acid (150) (15) (0.04) Sol. 44A-25(0.1) B-1(3.9) TPSMA — maleic PGEE water (0.04) acid (150) (15)(0.04) TPSOH: triphenylsulfonium hydroxide TPSHCO₃:mono-(triphenylsulfonium) carbonate TPSOx: mono-(triphenylsulfonium)oxalate TPSTFA: triphenylsulfonium trifluoroacetate TPSOCOPh:triphenylsulfonium benzoate TPSH₂PO₄: mono-(triphenylsulfonium)phosphate TPSMA: mono-(triphenylsulfonium) maleate TPSNf:triphenylsulfonium nonafluorobutan sulfonate QMAMA: mono-(tetramethylammonium) maleate QMATFA: tetramethyl ammonium trifluoroacetate QBANO₃:tetrabuthyl ammonium nitrate Ph₂ICl: diphenyl iodonium chlorideMeasurement of Contact Angles:Contact Angle of the Silicon-Containing Resist Underlayer Film (CA1)

Each of the composition solutions Sol.1 to Sol.44 for forming a resistunderlayer film was applied on a substrate and then heated at 240° C.for 60 seconds to obtain respective silicon-containing resist underlayerfilms Film-1 to Film-44 having film thickness of 35 nm; and then, thecontact angle thereof to pure water (CA1) was measured (Table 4).

Contact Angle of the Silicon-Containing Resist Underlayer Film afterPhotoresist Coating for the Positive Development and Removal of it (CA2)

Each of the composition solutions Sol.1 to Sol.44 for forming asilicon-containing resist underlayer film was applied onto a siliconwafer and then heated at 240° C. for 60 seconds to obtain respectivesilicon-containing resist underlayer films Film-1 to Film-44 having filmthickness of 35 nm. Onto it was applied the ArF resist solution shown inTable 9 (PR-1), and then baked at 100° C. for 60 seconds to form aphotoresist film having film thickness of 100 nm. Then, entirety of thephotoresist film was removed by rinsing with propylene glycol monomethylether (PGME) to obtain a film that is equivalent to thesilicon-containing resist underlayer film corresponding to an unexposedarea of the unexposed photoresist film. Contact angles of these films topure water (CA2) were measured (Table 5).

Contact Angle of the Silicon-Containing Resist Underlayer Film afterPhotoresist Coating for the Negative Development and Removal of it (CA3)

Each of the composition solutions Sol.1 to Sol.44 for forming asilicon-containing resist underlayer film was applied onto a siliconwafer and then heated at 240° C. for 60 seconds to obtain respectivesilicon-containing resist underlayer films Film-1 to Film-44 having filmthickness of 35 nm. Onto it was applied the ArF resist solution for thenegative development shown in Table 12 (PR-3), and then baked at 100° C.for 60 seconds to form a photoresist film having film thickness of 100nm. Further, the photoresist film was applied with the immersion topcoat shown in Table 10 (TC-1), and baked at 90° C. for 60 seconds toform a top coat having film thickness of 50 nm. Then, entirety of theimmersion top coat and the photoresist film were removed by rinsing withpropylene glycol monomethyl ether (PGME) to obtain a film that isequivalent the silicon-containing resist underlayer film correspondingto an unexposed area of the unexposed photoresist film. Contact anglesof these films to pure water (CA3) were measured (Table 6).

Contact Angle of the Silicon-Containing Resist Underlayer Film afterPhotoresist Coating for the Negative Development, Photo-Exposure, andRemoval of it (CA4)

Each of the composition solutions Sol.1 to Sol.44 for forming asilicon-containing resist underlayer film was applied onto a siliconwafer and then heated at 240° C. for 60 seconds to obtain respectivesilicon-containing underlayer films Film-1 to Film-44 having filmthickness of 35 nm. Onto it was applied the ArF resist solution for thenegative development shown in Table 12 (PR-3), and then baked at 100° C.for 60 seconds to form a photoresist film having film thickness of 100nm. Further, the photoresist film was applied with the immersion topcoat shown in Table 10 (TC-1), and then baked at 90° C. for 60 secondsto form a top coat having film thickness of 50 nm. Then, entirety of itwas exposed by using an ArF immersion exposure instrument (NSR-S610C,manufactured by Nikon Corp.), baked at 100° C. for 60 seconds (PEB),poured with a butyl acetate developer for 3 seconds from a developernozzle while rotating at 30 rpm, developed by a puddle developmentmethod for 27 seconds without rotation, spin-dried after rinsing withdiisoamyl ether, and then baked at 100° C. for 20 seconds to remove therinsing solvent by evaporation. Entirety of the remained photoresistfilm was removed by rinsing with PGME to obtain a film that isequivalent the silicon-containing resist underlayer film correspondingto an exposed area of the exposed photoresist film. Contact angles ofthese films to pure water (CA4) were measured (Table 7).

Contact Angles of the Photoresist Film for the Negative DevelopmentBefore and after Photo-Exposure

Each ArF resist solution for the negative development shown in Table 12(PR-3 and PR-4) was applied and then baked at 100° C. for 60 seconds toprepare the photoresist film having film thickness of 100 nm; and then,contact angle thereof to pure water was measured. Then, entirety of thisresist film was exposed by using an ArF exposure instrument (NSR-S610C,manufactured by Nikon Corp.), baked at 100° C. for 60 seconds (PEB),spin-dried after rinsing with diisoamyl ether, and then baked at 100° C.for 20 seconds to remove the rinsing solvent by evaporation to obtainthe ArF resist film corresponding to the patterned area not having theacid-labile group at the time of negative development. Contact anglethereof to pure water was measured (Table 8).

TABLE 4 Contact No. angle Film 1 73° Film 2 71° Film 3 74° Film 4 72°Film 5 71° Film 6 73° Film 7 70° Film 8 74° Film 9 72° Film 10 70° Film11 70° Film 12 73° Film 13 71° Film 14 71° Film 15 69° Film 16 71° Film17 73° Film 18 70° Film 19 73° Film 20 71° Film 21 73° Film 22 71° Film23 72° Film 24 72° Film 25 73° Film 26 69° Film 27 76° Film 28 77° Film29 71° Film 30 70° Film 31 70° Film 32 72° Film 33 74° Film 34 71° Film35 73° Film 36 73° Film 37 74° Film 38 69° Film 39 72° Film 40 73° Film41 71° Film 42 75° Film 43 70° Film 44 77°

TABLE 5 Contact No. angle Film 1 65° Film 2 63° Film 3 65° Film 4 66°Film 5 64° Film 6 64° Film 7 64° Film 8 64° Film 9 65° Film 10 66° Film11 64° Film 12 66° Film 13 65° Film 14 65° Film 15 65° Film 16 65° Film17 64° Film 18 64° Film 19 65° Film 20 65° Film 21 64° Film 22 66° Film23 64° Film 24 65° Film 25 64° Film 26 61° Film 27 67° Film 28 69° Film29 63° Film 30 65° Film 31 64° Film 32 66° Film 33 67° Film 34 65° Film35 66° Film 36 64° Film 37 64° Film 38 64° Film 39 64° Film 40 65° Film41 63° Film 42 68° Film 43 61° Film 44 64°

TABLE 6 Contact No. angle Film 1 64° Film 2 63° Film 3 65° Film 4 64°Film 5 64° Film 6 64° Film 7 63° Film 8 64° Film 9 65° Film 10 66° Film11 64° Film 12 63° Film 13 65° Film 14 65° Film 15 64° Film 16 65° Film17 65° Film 18 64° Film 19 65° Film 20 65° Film 21 64° Film 22 63° Film23 64° Film 24 66° Film 25 64° Film 26 63° Film 27 68° Film 28 69° Film29 64° Film 30 65° Film 31 63° Film 32 66° Film 33 64° Film 34 65° Film35 63° Film 36 64° Film 37 64° Film 38 63° Film 39 64° Film 40 64° Film41 64° Film 42 68° Film 43 62° Film 44 64°

TABLE 7 Contact No. angle Film 1 45° Film 2 48° Film 3 49° Film 4 48°Film 5 48° Film 6 48° Film 7 52° Film 8 46° Film 9 47° Film 10 47° Film11 52° Film 12 48° Film 13 48° Film 14 45° Film 15 46° Film 16 50° Film17 49° Film 18 45° Film 19 49° Film 20 50° Film 21 47° Film 22 47° Film23 47° Film 24 47° Film 25 45° Film 26 46° Film 27 52° Film 28 50° Film29 48° Film 30 53° Film 31 53° Film 32 50° Film 33 46° Film 34 48° Film35 49° Film 36 48° Film 37 49° Film 38 47° Film 39 49° Film 40 46° Film41 49° Film 42 47° Film 43 49° Film 44 62°

TABLE 8 Contact Contact No. angle No. angle unexposed PR-3 71° exposedPR-3 53° unexposed PR-4 73° exposed PR-4 56°Patterning Test by the Positive Development

Onto a silicon wafer was formed a spin-on carbon film ODL-50 (carboncontent of 80% by mass, manufactured by Shin-Etsu Chemical Co., Ltd.)having film thickness of 200 nm. Onto this was applied each of thecomposition solutions Sol.11 to Sol.44 for forming a resist underlayerfilm, and then baked at 240° C. for 60 seconds to obtain the respectivesilicon-containing resist underlayer films Film-11 to Film-44 havingfilm thickness of 35 nm.

Thereafter, onto this silicon-containing resist underlayer film wasapplied the ArF resist solution for the positive development shown inTable 9 (PR-1), and then baked at 110° C. for 60 seconds to obtain thephotoresist film having film thickness of 100 nm. Further, thephotoresist film was applied with the immersion top coat shown in Table10 (TC-1), and then baked at 90° C. for 60 seconds to obtain the topcoat having film thickness of 50 nm (Examples 1-1 to 1-32 andComparative Examples 1-1 to 1-2).

Then, this was exposed by using an ArF immersion exposure instrument(NSR-S610C, manufactured by Nikon Corp., NA 1.30, σ 0.98/0.65, 35 degreedipolar polarized illumination, 6% half tone phase shift mask), baked at100° C. for 60 seconds (PEB), and then developed by an aqueoustetramethylammonium hydroxide (TMAH) solution (concentration of 2.38% bymass) for 30 seconds to obtain the 43-nm 1:1 positive line-and-spacepattern.

As to this size, pattern fall was measured with an electron microscope(CG 4000, manufactured by Hitachi High-technologies Corp.) and patternprofile of cross section was measured with an electron microscope(S-9380, manufactured by Hitachi, Ltd.) (Table 11).

TABLE 9 Acid Water-shedding Solvent Polymer generator Base polymer(parts (parts by (parts by (parts (parts by by No. mass) mass) by mass)mass) mass) PR-1 ArF resist PAG1 Quencher — PGMEA polymer 1  (7.0) (1.0)(2,500) (100) PR-2 ArF resist PAG1 Quencher Water-shedding PGMEA polymer1 (10.0) (2.0) polymer 1 (2,500) (100) (4.0)ArF Resist Polymer 1:

Molecular weight (Mw)=7,800

Distribution (Mw/Mn)=1.78

Acid Generator: PAG 1

Base: Quencher

Water-Shedding Polymer 1:

Molecular weight (Mw)=8,200

Distribution (Mw/Mn)=1.67

Top-Coat Polymer:

Molecular weight (Mw)=8,800

Distribution (Mw/Mn)=1.69

TABLE 10 Polymer Organic solvent (parts by mass) (parts by mass) TC-1Top-coat polymer diisoamylether (2700) (100) 2-methyl-1-butanol (270)

TABLE 11 Silicon- Pattern containing profile of resist cross underlayerArF section after Pattern Examples film resist development collapseCA1-CA2 Example 1-1 Film11 PR-1 vertical free 4° profile Example 1-2Film12 PR-1 vertical free 7° profile Example 1-3 Film13 PR-1 verticalfree 6° profile Example 1-4 Film14 PR-1 vertical free 6° profile Example1-5 Film15 PR-1 vertical free 4° profile Example 1-6 Film16 PR-1vertical free 6° profile Example 1-7 Film17 PR-1 vertical free 9°profile Example 1-8 Film18 PR-1 vertical free 6° profile Example 1-9Film19 PR-1 vertical free 8° profile Example 1-10 Film20 PR-1 verticalfree 6° profile Example 1-11 Film21 PR-1 vertical free 9° profileExample 1-12 Film22 PR-1 vertical free 5° profile Example 1-13 Film23PR-1 vertical free 8° profile Example 1-14 Film24 PR-1 vertical free 7°profile Example 1-15 Film25 PR-1 vertical free 9° profile Example 1-16Film26 PR-1 vertical free 8° profile Example 1-17 Film27 PR-1 verticalfree 9° profile Example 1-18 Film28 PR-1 vertical free 8° profileExample 1-19 Film29 PR-1 vertical free 8° profile Example 1-20 Film30PR-1 vertical free 5° profile Example 1-21 Film31 PR-1 vertical free 6°profile Example 1-22 Film32 PR-1 vertical free 6° profile Example 1-23Film33 PR-1 vertical free 7° profile Example 1-24 Film34 PR-1 verticalfree 6° profile Example 1-25 Film35 PR-1 vertical free 7° profileExample 1-26 Film36 PR-1 vertical free 9° profile Example 1-27 Film37PR-1 vertical free 10°  profile Example 1-28 Film38 PR-1 vertical free5° profile Example 1-29 Film39 PR-1 vertical free 8° profile Example1-30 Film40 PR-1 vertical free 8° profile Example 1-31 Film41 PR-1vertical free 8° profile Example 1-32 Film42 PR-1 vertical free 7°profile Comparative Film43 PR-1 vertical free 8° Example 1-1 profileComparative Film44 PR-1 vertical free 7° Example 1-2 profile

As shown in Table 11, when the silicon-containing resist underlayer filmhaving the change amount of 10 degrees or less between the contact angle(CA1) of the silicon-containing resist underlayer film and the contactangle (CA2) of the silicon-containing resist underlayer film aftercoating with the photoresist for the positive development and removal ofit was used as the resist underlayer film, a vertical profile in theresist cross section could be obtained in the positive development. Itwas also confirmed that there was no pattern fall.

Patterning Test by the Negative Development

Onto a silicon wafer was formed a spin-on carbon film ODL-50 (carboncontent of 80% by mass, manufactured by Shin-Etsu Chemical Co., Ltd.)having film thickness of 200 nm. Onto this was applied each of thecomposition solutions Sol.11 to Sol.44 for forming a resist underlayerfilm, and then baked at 240° C. for 60 seconds to obtain the respectivesilicon-containing resist underlayer films Film-11 to Film-44 havingfilm thickness of 35 nm.

Thereafter, onto this silicon-containing resist underlayer film wasapplied the ArF resist solution for the negative development shown inTable 12 (PR-3), and then baked at 100° C. for 60 seconds to obtain thephotoresist film having film thickness of 100 nm. Further, thephotoresist film was applied with the immersion top coat shown in Table10 (TC-1), and then baked at 90° C. for 60 seconds to obtain the topcoat having film thickness of 50 nm (Examples 2-1 to 2-32 andComparative Examples 2-1 to 2-2).

Then, this was exposed by using an ArF immersion exposure instrument(NSR-S610C, manufactured by Nikon Corp., NA 1.30, σ 0.98/0.65, 35 degreedipolar polarized illumination, 6% half tone phase shift mask), baked at100° C. for 60 seconds (PEB), poured with a butyl acetate developer for3 seconds from a developer nozzle while rotating at 30 rpm, developed bya puddle development method for 27 seconds without rotation, spin-driedafter rinsing with diisoamyl ether, and then baked at 100° C. for 20seconds to remove the rinsing solvent by evaporation.

By this patterning, the negative 43-nm 1:1 line-and-space pattern wasobtained. As to this size, pattern fall was measured with an electronmicroscope (CG 4000, manufactured by Hitachi High-technologies Corp.)and pattern profile of cross section was measured with an electronmicroscope (S-4700, manufactured by Hitachi, Ltd.) (Table 13).

TABLE 12 Acid Water-shedding Polymer generator Base polymer Solvent(parts by (parts by (parts (parts by (parts No. mass) mass) by mass)mass) by mass) PR-3 ArF resist PAG2 Quencher — PGMEA polymer 2 (7.0)(1.0) (2,500) (100) PR-4 ArF resist PAG2 Quencher — PGMEA polymer 3(7.0) (1.0) (2,500) (100) PR-5 ArF resist PAG2 Quencher Water-sheddingPGMEA polymer 3 (10.0)  (2.0) polymer 1 (2,500) (100) (4.0)ArF Resist Polymer 2:

Molecular weight (Mw)=8,600

Distribution (Mw/Mn)=1.88

ArF Resist Polymer 3:

Molecular weight (Mw)=8,900

Distribution (Mw/Mn)=1.93

Acid Generator: PAG 2

Base: Quencher

TABLE 13 Silicon- Pattern containing profile of resist cross underlayerArF section after Pattern Examples film resist development collapseCA3-CA4 Example 2-1 Film11 PR-3 vertical free 12° profile Example 2-2Film12 PR-3 vertical free 15° profile Example 2-3 Film13 PR-3 verticalfree 17° profile Example 2-4 Film14 PR-3 vertical free 20° profileExample 2-5 Film15 PR-3 vertical free 18° profile Example 2-6 Film16PR-3 vertical free 15° profile Example 2-7 Film17 PR-3 vertical free 16°profile Example 2-8 Film18 PR-3 vertical free 19° profile Example 2-9Film19 PR-3 vertical free 16° profile Example 2-10 Film20 PR-3 verticalfree 15° profile Example 2-11 Film21 PR-3 vertical free 17° profileExample 2-12 Film22 PR-3 vertical free 16° profile Example 2-13 Film23PR-3 vertical free 17° profile Example 2-14 Film24 PR-3 vertical free19° profile Example 2-15 Film25 PR-3 vertical free 19° profile Example2-16 Film26 PR-3 vertical free 17° profile Example 2-17 Film27 PR-3vertical free 16° profile Example 2-18 Film28 PR-3 vertical free 19°profile Example 2-19 Film29 PR-3 vertical free 16° profile Example 2-20Film30 PR-3 vertical free 18° profile Example 2-21 Film31 PR-3 verticalfree 10° profile Example 2-22 Film32 PR-3 vertical free 16° profileExample 2-23 Film33 PR-3 vertical free 18° profile Example 2-24 Film34PR-3 vertical free 17° profile Example 2-25 Film35 PR-3 vertical free16° profile Example 2-26 Film36 PR-3 vertical free 16° profile Example2-27 Film37 PR-3 vertical free 15° profile Example 2-28 Film38 PR-3vertical free 16° profile Example 2-29 Film39 PR-3 vertical free 15°profile Example 2-30 Film40 PR-3 vertical free 17° profile Example 2-31Film41 PR-3 vertical free 15° profile Example 2-32 Film42 PR-3 verticalfree 21° profile Comparative Film43 PR-3 vertical free 13° Example 2-1profile Comparative Film44 PR-3 vertical occurrence  2° Example 2-2profile

As shown in Table 13, when the silicon-containing resist underlayer filmhaving the change amount of 10 degrees or more between the contact angle(CA3) of the silicon-containing resist underlayer film after coatingwith the photoresist for the negative development and removal of it andthe contact angle (CA4) of the silicon-containing resist underlayer filmafter coating with the photoresist for the negative development,exposure, and removal of it was used as the resist underlayer film, avertical profile in the resist cross section could be obtained in thenegative development. It was also confirmed that there was no patternfall. On the other hand, in the negative development of ComparativeExample 2-2 not containing an organic group substituted with anacid-labile group, the change amount of the contact angle was so smallthat pattern fall occurred.

Patterning Test: Developer

By following the procedures similar to those of Example 2 except thatArF resists and developers shown below were used instead of thedeveloper (butyl acetate) used in Example 2, the negative 43-nm 1:1line-and-space pattern of Film-11 was obtained by using the compositionsolution Sol.11 for forming a resist underlayer film. These results areshown in Table 14. By using these various developers, a resist patternhaving a vertical profile of its cross section could be obtained(Examples 3-1 to 3-6).

TABLE 14 Silicon- Pattern containing profile of resist cross sectionunderlayer ArF after Pattern film resist Developer development collapseExample Film11 PR-3 2-heptanone vertical free 3-1 profile Example Film11PR-3 methyl vertical free 3-2 benzoate profile Example Film11 PR-4 ethylvertical free 3-3 benzoate profile Example Film11 PR-4 phenyl verticalfree 3-4 acetate profile Example Film11 PR-5 benzyl vertical free 3-5acetate profile Example Film11 PR-5 methyl vertical free 3-6phenylacetate profilePattern Etching Test: Positive Pattern

Similarly to Example 1, silicon-containing resist underlayer filmsFilm-11 to Film-40 and Film-43 were prepared; and onto each of thesesilicon-containing resist underlayer films was applied the ArF resistsolution for the positive development shown in Table 9 (PR-1), and thenbaked at 110° C. for 60 seconds to form the photoresist film having filmthickness of 100 nm. Onto the photoresist film was applied the immersiontop coat shown in Table 10 (TC-1), and then baked at 90° C. for 60seconds to form the top coat having film thickness of 50 nm (Examples4-1 to 4-10, 4-21 to 4-30, and Comparative Example 4-1).

Separately from the above, the ArF resist solution for positivedevelopment shown in Table 9 (PR-2) was applied onto thesilicon-containing resist underlayer film, and then baked at 110° C. for60 seconds to form the photoresist film having film thickness of 100 nm(Examples 4-11 to 4-20).

By using the resist pattern thus obtained by the positive development asa mask, the silicon-containing resist underlayer film was dry-etchedunder the following condition (1) and then dry-etched under thefollowing condition (2) to transfer the pattern onto the spin-on carbonfilm. Pattern profile of cross section of the obtained pattern wasmeasured with an electron microscope (S-9380, manufactured by Hitachi,Ltd.) and pattern roughness was measured with an electron microscope (CG4000, manufactured by Hitachi High-technologies Corp.); and they werecompared as summarized in Table 15.

(1) Etching Condition in the CHF₃/CF₄ Gas System

Instrument: dry etching instrument Telius SP (manufactured by TokyoElectron Ltd.)

Etching Condition (1):

Chamber pressure 10 Pa Upper/Lower RF power 500 W/300 W CHF₃ gas flowrate 50 mL/minute CF₄ gas flow rate 150 mL/minute Ar gas flow rate 100mL/minute Treatment time 40 seconds(2) Etching Condition in the O₂/N₂ Gas SystemInstrument: dry etching instrument Telius SP (manufactured by TokyoElectron Ltd.)Etching Condition (2):

Chamber pressure 2 Pa Upper/Lower RF power 1000 W/300 W O₂ gas flow rate300 mL/minute N₂ gas flow rate 100 mL/minute Ar gas flow rate 100mL/minute Treatment time 30 seconds

TABLE 15 Silicon- Pattern profile of containing cross section of resistspin-on carbon underlayer ArF film after dry Pattern Examples filmresist etching roughness Example 4-1 Film11 PR-1 vertical profile 1.7 nmExample 4-2 Film12 PR-1 vertical profile 1.5 nm Example 4-3 Film13 PR-1vertical profile 2.0 nm Example 4-4 Film14 PR-1 vertical profile 1.7 nmExample 4-5 Film15 PR-1 vertical profile 1.6 nm Example 4-6 Film16 PR-1vertical profile 1.9 nm Example 4-7 Film17 PR-1 vertical profile 1.6 nmExample 4-8 Film18 PR-1 vertical profile 2.2 nm Example 4-9 Film19 PR-1vertical profile 1.8 nm Example 4-10 Film20 PR-1 vertical profile 1.7 nmExample 4-11 Film21 PR-2 vertical profile 1.8 nm Example 4-12 Film22PR-2 vertical profile 1.8 nm Example 4-13 Film23 PR-2 vertical profile1.6 nm Example 4-14 Film24 PR-2 vertical profile 2.1 nm Example 4-15Film25 PR-2 vertical profile 2.1 nm Example 4-16 Film26 PR-2 verticalprofile 1.9 nm Example 4-17 Film27 PR-2 vertical profile 2.0 nm Example4-18 Film28 PR-2 vertical profile 1.6 nm Example 4-19 Film29 PR-2vertical profile 2.1 nm Example 4-20 Film30 PR-2 vertical profile 1.7 nmExample 4-21 Film31 PR-1 vertical profile 1.5 nm Example 4-22 Film32PR-1 vertical profile 2.1 nm Example 4-23 Film33 PR-1 vertical profile2.0 nm Example 4-24 Film34 PR-1 vertical profile 2.1 nm Example 4-25Film35 PR-1 vertical profile 1.9 nm Example 4-26 Film36 PR-1 verticalprofile 1.9 nm Example 4-27 Film37 PR-1 vertical profile 1.6 nm Example4-28 Film38 PR-1 vertical profile 2.0 nm Example 4-29 Film39 PR-1vertical profile 2.1 nm Example 4-30 Film40 PR-1 vertical profile 1.9 nmComparative Film43 PR-1 vertical profile 4.1 nm Example 4-1

In the present invention, as can be seen in Table 15, it was found thatnot only resist profile after development, but also pattern profile ofcross section and pattern roughness after processing of the spin-oncarbon film were excellent. On the other hand, in the silicon-containingfilm formed of only a silicon compound as the comparative example(Comparative Example 4-1), etching resistance of the component locallypresent near surface is comparatively high; and thus, during the time ofdry etching of the resist underlayer film by using the upperlayer resistpattern as a mask, the upperlayer resist is damaged, which is observedfinally as pattern roughness after processing of the spin-on carbonfilm.

Pattern Etching Test: Negative Pattern

Similarly to Example 2, silicon-containing resist underlayer filmsFilm-11 to Film-40 and Film-43 were prepared; and onto each of thesesilicon-containing resist underlayer films was applied the ArF resistsolution for the negative development shown in Table 12 (PR-3 and PR-4),and then baked at 100° C. for 60 seconds to form the photoresist filmhaving film thickness of 100 nm. Onto the photoresist film was appliedthe immersion top coat shown in Table 10 (TC-1), and then baked at 90°C. for 60 seconds to form the top coat having film thickness of 50 nm(Examples 5-1 to 5-20, 5-29 to 5-30, and Comparative Example 5-1).

Separately from the above, the ArF resist solution for the negativedevelopment shown in Table 12 (PR-5) was applied onto thesilicon-containing resist underlayer film, and then baked at 110° C. for60 seconds to form the photoresist film having film thickness of 100 nm(Examples 5-21 to 5-28).

By using the resist pattern thus obtained by the negative development asa mask, the silicon-containing resist underlayer film was dry-etchedunder the above condition (1) and then dry-etched under the abovecondition (2) to transfer the pattern onto the spin-on carbon film.Pattern profile of cross section of the obtained pattern was measuredwith an electron microscope (S-9380, manufactured by Hitachi, Ltd.) andpattern roughness was measured with an electron microscope (CG 4000,manufactured by Hitachi High-technologies Corp.); and they were comparedas summarized in Table 16.

TABLE 16 Silicon- Pattern profile of containing cross section of resistspin-on carbon underlayer ArF film after dry Pattern Examples filmresist etching roughness Example 5-1 Film11 PR-3 vertical profile 1.7 nmExample 5-2 Film12 PR-3 vertical profile 1.8 nm Example 5-3 Film13 PR-3vertical profile 1.8 nm Example 5-4 Film14 PR-3 vertical profile 2.2 nmExample 5-5 Film15 PR-3 vertical profile 1.7 nm Example 5-6 Film16 PR-3vertical profile 1.7 nm Example 5-7 Film17 PR-3 vertical profile 1.5 nmExample 5-8 Film18 PR-3 vertical profile 2.1 nm Example 5-9 Film19 PR-3vertical profile 1.5 nm Example 5-10 Film20 PR-3 vertical profile 1.7 nmExample 5-11 Film21 PR-4 vertical profile 1.7 nm Example 5-12 Film22PR-4 vertical profile 2.1 nm Example 5-13 Film23 PR-4 vertical profile1.7 nm Example 5-14 Film24 PR-4 vertical profile 1.9 nm Example 5-15Film25 PR-4 vertical profile 1.9 nm Example 5-16 Film26 PR-4 verticalprofile 2.2 nm Example 5-17 Film27 PR-4 vertical profile 1.6 nm Example5-18 Film28 PR-4 vertical profile 1.9 nm Example 5-19 Film29 PR-4vertical profile 1.6 nm Example 5-20 Film30 PR-4 vertical profile 2.0 nmExample 5-21 Film31 PR-5 vertical profile 2.0 nm Example 5-22 Film32PR-5 vertical profile 2.1 nm Example 5-23 Film33 PR-5 vertical profile2.0 nm Example 5-24 Film34 PR-5 vertical profile 2.0 nm Example 5-25Film35 PR-5 vertical profile 1.8 nm Example 5-26 Film36 PR-5 verticalprofile 1.6 nm Example 5-27 Film37 PR-5 vertical profile 2.0 nm Example5-28 Film38 PR-5 vertical profile 2.0 nm Example 5-29 Film39 PR-3vertical profile 2.2 nm Example 5-30 Film40 PR-3 vertical profile 2.1 nmComparative Film43 PR-3 vertical profile 4.5 nm Example 5-1

In the present invention, as can be seen in Table 16, it was found thatnot only resist profile after development, but also pattern profile ofcross section and pattern roughness after processing of the spin-oncarbon film were excellent. On the other hand, in the silicon-containingfilm formed of only a silicon compound as the comparative example(Comparative Example 5-1), etching resistance of the component locallypresent near surface is comparatively high; and thus, during the time ofdry etching of the resist underlayer film by using the upperlayer resistpattern as a mask, the upperlayer resist is damaged, which is observedfinally as pattern roughness after processing of the spin-on carbonfilm.

As explained above, the present invention can provide (i) thecomposition for forming a silicon-containing resist underlayer film thatis applicable not only to a resist pattern formed of a hydrophilicorganic compound obtained by a negative development but also a resistpattern formed of a hydrophobic compound obtained by a conventionalpositive development, and (ii) the patterning process using thiscomposition.

The present invention is not limited to the above embodiments. The aboveembodiments are merely illustrative, and whatever having thesubstantially same configurations as the technical concept recited inthe appended claims and exhibiting the same functions and effects areembraced within the technical scope of the present invention.

What is claimed is:
 1. A composition for forming a silicon-containingresist underlayer film comprising: (A) a silicon-containing compoundobtained by a hydrolysis-condensation reaction of a mixture containing,at least, one or more hydrolysable silicon compound shown by thefollowing general formula (1) and one or more hydrolysable compoundshown by the following general formula (2),R¹ _(m1)R² _(m2)R³ _(m3)Si(OR)_((4-m1-m2-m3))  (1) wherein, R representsa hydrocarbon group having 1 to 6 carbon atoms; at least one of R¹, R²,and R³ is an organic group containing a hydroxyl group or a carboxylgroup, the groups being substituted with an acid-labile group, while theother is a hydrogen atom or a monovalent organic group having 1 to 30carbon atoms; and m1, m2, and m3 represent 0 or 1 and satisfy1≦m1+m2+m3≦3;U(OR⁴)_(m4)(OR⁵)_(m5)  (2) wherein, R⁴ and R⁵ represent an organic grouphaving 1 to 30 carbon atoms, and m4+m5 is the same number as the numberdetermined by valency of U; m4 and m5 represent an integer of 0 or more;and the U is an element belonging to groups of III, IV, or V in aperiodic table except for carbon and silicon; and (B) asilicon-containing compound obtained by a hydrolysis-condensationreaction of a mixture containing, at least, one or more hydrolysablesilicon compound shown by the following general formula (3) and one ormore hydrolysable silicon compound shown by the following generalformula (4),R⁶ _(m6)R⁷ _(m7)R⁸ _(m8)Si(OR⁹)_((4-m6-m7-m8))  (3) wherein, R⁹represents an alkyl group having 1 to 6 carbon atoms, and each R⁶, R⁷,and R⁸ represents a hydrogen atom or a monovalent organic group having 1to 30 carbon atoms; and m6, m7, and m8 represent 0 or 1 and satisfy1≦m6+m7+m8≦3;Si(OR¹⁰)₄  (4) wherein, R¹⁰ represents an alkyl group having 1 to 6carbonatoms, and of the constituting units derived from the generalformula (3) and the general formula (4) in the component (B), a moleratio of the constituting unit derived from the general formula (4) is50% or more by mole, and the composition is effective to provide asilicon-containing resist underlayer film having a pure-water contactangle of from 40 degrees or more to lower than 70 degrees afterexposure.
 2. The composition for forming a silicon-containing resistunderlayer film according to claim 1, wherein mass ratio of thecomponent (A) to the component (B) satisfies (B)/(A)≧1.
 3. Thecomposition for forming a silicon-containing resist underlayer filmaccording to claim 2, wherein the U of the general formula (2) is any ofboron, aluminum, gallium, yttrium, germanium, titanium, zirconium,hafnium, bismuth, tin, phosphorous, vanadium, arsenic, antimony,niobium, and tantalum.
 4. A patterning process, wherein an organicunderlayer film is formed on a body to be processed by using anapplication-type composition for the organic underlayer film, on thisorganic underlayer film is formed a silicon-containing resist underlayerfilm by using the composition for forming the silicon-containing resistunderlayer film according to claim 3, on this silicon-containing resistunderlayer film is formed a photoresist film by using a chemicallyamplified resist composition, the photoresist film is exposed to a highenergy beam after heat treatment, a positive pattern is formed bydissolving an exposed area of the photoresist film by using an alkalinedeveloper, pattern transfer is made onto the silicon-containing resistunderlayer film by dry-etching by using the photoresist film having thepositive pattern as a mask, pattern transfer is made onto the organicunderlayer film by dry-etching by using the silicon-containing resistunderlayer film having the transferred pattern as a mask, and thenpattern transfer is made onto the body to be processed by dry-etching byusing the organic underlayer film having the transferred pattern as amask.
 5. A patterning process, wherein an organic hard mask mainlycomprising carbon is formed on a body to be processed by a CVD method,on this organic hard mask is formed a silicon-containing resistunderlayer film by using the composition for forming thesilicon-containing resist underlayer film according to claim 3, on thissilicon-containing resist underlayer film is formed a photoresist filmby using a chemically amplified resist composition, the photoresist filmis exposed to a high energy beam after heat treatment, a positivepattern is formed by dissolving an exposed area of the photoresist filmby using an alkaline developer, pattern transfer is made onto thesilicon-containing resist underlayer film by dry-etching by using thephotoresist film having the positive pattern as a mask, pattern transferis made onto the organic hard mask by dry-etching by using thesilicon-containing resist underlayer film having the transferred patternas a mask, and then pattern transfer is made onto the body to beprocessed by dry-etching by using the organic hard mask having thetransferred pattern as a mask.
 6. A patterning process, wherein anorganic underlayer film is formed on a body to be processed by using anapplication-type composition for the organic underlayer film, on thisorganic underlayer film is formed a silicon-containing resist underlayerfilm by using the composition for forming the silicon-containing resistunderlayer film according to claim 3, on this silicon-containing resistunderlayer film is formed a photoresist film by using a chemicallyamplified resist composition, the photoresist film is exposed to a highenergy beam after heat treatment, a negative pattern is formed bydissolving an unexposed area of the photoresist film by using an organicsolvent developer, pattern transfer is made onto the silicon-containingresist underlayer film by dry-etching by using the photoresist filmhaving the negative pattern as a mask, pattern transfer is made onto theorganic underlayer film by dry-etching by using the silicon-containingresist underlayer film having the transferred pattern as a mask, andthen pattern transfer is made onto the body to be processed bydry-etching by using the organic underlayer film having the transferredpattern as a mask.
 7. A patterning process, wherein an organic hard maskmainly comprising carbon is formed on a body to be processed by a CVDmethod, on this organic hard mask is formed a silicon-containing resistunderlayer film by using the composition for forming thesilicon-containing resist underlayer film according to claim 3, on thissilicon-containing resist underlayer film is formed a photoresist filmby using a chemically amplified resist composition, the photoresist filmis exposed to a high energy beam after heat treatment, a negativepattern is formed by dissolving an unexposed area of the photoresistfilm by using an organic solvent developer, pattern transfer is madeonto the silicon-containing resist underlayer film by dry-etching byusing the photoresist film having the negative pattern as a mask,pattern transfer is made onto the organic hard mask by dry-etching byusing the silicon-containing resist underlayer film having thetransferred pattern as a mask, and then pattern transfer is made ontothe body to be processed by dry-etching by using the organic hard maskhaving the transferred pattern as a mask.
 8. The composition for forminga silicon-containing resist underlayer film according to claim 1,wherein the U of the general formula (2) is any of boron, aluminum,gallium, yttrium, germanium, titanium, zirconium, hafnium, bismuth, tin,phosphorous, vanadium, arsenic, antimony, niobium, and tantalum.
 9. Apatterning process, wherein an organic underlayer film is formed on abody to be processed by using an application-type composition for theorganic underlayer film, on this organic underlayer film is formed asilicon-containing resist underlayer film by using the composition forforming the silicon-containing resist underlayer film according to claim1, on this silicon-containing resist underlayer film is formed aphotoresist film by using a chemically amplified resist composition, thephotoresist film is exposed to a high energy beam after heat treatment,a positive pattern is formed by dissolving an exposed area of thephotoresist film by using an alkaline developer, pattern transfer ismade onto the silicon-containing resist underlayer film by dry-etchingby using the photoresist film having the positive pattern as a mask,pattern transfer is made onto the organic underlayer film by dry-etchingby using the silicon-containing resist underlayer film having thetransferred pattern as a mask, and then pattern transfer is made ontothe body to be processed by dry-etching by using the organic underlayerfilm having the transferred pattern as a mask.
 10. The patterningprocess according to claim 9, wherein, in photo-exposure of thephotoresist film, change of the contact angle in a part of thesilicon-containing resist underlayer film corresponding to an unexposedarea of the exposed photoresist film is 10 degree or less as comparedwith before photo-exposure.
 11. The patterning process according toclaim 9, wherein the body to be processed is a substrate for asemiconductor device, or the substrate for a semiconductor devicecoated, as a layer to be processed, with any of a metal film, a metalcarbide film, a metal oxide film, a metal nitride film, a metaloxycarbide film, and a metal oxynitride film.
 12. The patterning processaccording to claim 11, wherein the metal that constitutes the body to beprocessed is silicon, titanium, tungsten, hafnium, zirconium, chromium,germanium, copper, aluminum, iron, or an alloy of these metals.
 13. Apatterning process, wherein an organic hard mask mainly comprisingcarbon is formed on a body to be processed by a CVD method, on thisorganic hard mask is formed a silicon-containing resist underlayer filmby using the composition for forming the silicon-containing resistunderlayer film according to claim 1, on this silicon-containing resistunderlayer film is formed a photoresist film by using a chemicallyamplified resist composition, the photoresist film is exposed to a highenergy beam after heat treatment, a positive pattern is formed bydissolving an exposed area of the photoresist film by using an alkalinedeveloper, pattern transfer is made onto the silicon-containing resistunderlayer film by dry-etching by using the photoresist film having thepositive pattern as a mask, pattern transfer is made onto the organichard mask by dry-etching by using the silicon-containing resistunderlayer film having the transferred pattern as a mask, and thenpattern transfer is made onto the body to be processed by dry-etching byusing the organic hard mask having the transferred pattern as a mask.14. The patterning process according to claim 13, wherein, inphoto-exposure of the photoresist film, change of the contact angle in apart of the silicon-containing resist underlayer film corresponding toan unexposed area of the exposed photoresist film is 10 degree or lessas compared with before photo-exposure.
 15. The patterning processaccording to claim 13, wherein the body to be processed is a substratefor a semiconductor device, or the substrate for a semiconductor devicecoated, as a layer to be processed, with any of a metal film, a metalcarbide film, a metal oxide film, a metal nitride film, a metaloxycarbide film, and a metal oxynitride film.
 16. The patterning processaccording to claim 15, wherein the metal that constitutes the body to beprocessed is silicon, titanium, tungsten, hafnium, zirconium, chromium,germanium, copper, aluminum, iron, or an alloy of these metals.
 17. Apatterning process, wherein an organic underlayer film is formed on abody to be processed by using an application-type composition for theorganic underlayer film, on this organic underlayer film is formed asilicon-containing resist underlayer film by using the composition forforming the silicon-containing resist underlayer film according to claim1, on this silicon-containing resist underlayer film is formed aphotoresist film by using a chemically amplified resist composition, thephotoresist film is exposed to a high energy beam after heat treatment,a negative pattern is formed by dissolving an unexposed area of thephotoresist film by using an organic solvent developer, pattern transferis made onto the silicon-containing resist underlayer film bydry-etching by using the photoresist film having the negative pattern asa mask, pattern transfer is made onto the organic underlayer film bydry-etching by using the silicon-containing resist underlayer filmhaving the transferred pattern as a mask, and then pattern transfer ismade onto the body to be processed by dry-etching by using the organicunderlayer film having the transferred pattern as a mask.
 18. Thepatterning process according to claim 17, wherein, in photo-exposure ofthe photoresist film, the contact angle of a part of thesilicon-containing resist underlayer film corresponding to an exposedarea of the exposed photoresist film is decreased by 10 degrees or moreafter photo-exposure as compared with before photo-exposure.
 19. Thepatterning process according to claim 17, wherein the body to beprocessed is a substrate for a semiconductor device, or the substratefor a semiconductor device coated, as a layer to be processed, with anyof a metal film, a metal carbide film, a metal oxide film, a metalnitride film, a metal oxycarbide film, and a metal oxynitride film. 20.The patterning process according to claim 19, wherein the metal thatconstitutes the body to be processed is silicon, titanium, tungsten,hafnium, zirconium, chromium, germanium, copper, aluminum, iron, or analloy of these metals.
 21. A patterning process, wherein an organic hardmask mainly comprising carbon is formed on a body to be processed by aCVD method, on this organic hard mask is formed a silicon-containingresist underlayer film by using the composition for forming thesilicon-containing resist underlayer film according to claim 1, on thissilicon-containing resist underlayer film is formed a photoresist filmby using a chemically amplified resist composition, the photoresist filmis exposed to a high energy beam after heat treatment, a negativepattern is formed by dissolving an unexposed area of the photoresistfilm by using an organic solvent developer, pattern transfer is madeonto the silicon-containing resist underlayer film by dry-etching byusing the photoresist film having the negative pattern as a mask,pattern transfer is made onto the organic hard mask by dry-etching byusing the silicon-containing resist underlayer film having thetransferred pattern as a mask, and then pattern transfer is made ontothe body to be processed by dry-etching by using the organic hard maskhaving the transferred pattern as a mask.
 22. The patterning processaccording to claim 21, wherein, in photo-exposure of the photoresistfilm, the contact angle of a part of the silicon-containing resistunderlayer film corresponding to an exposed area of the exposedphotoresist film is decreased by 10 degrees or more after photo-exposureas compared with before photo-exposure.
 23. The patterning processaccording to claim 21, wherein the body to be processed is a substratefor a semiconductor device, or the substrate for a semiconductor devicecoated, as a layer to be processed, with any of a metal film, a metalcarbide film, a metal oxide film, a metal nitride film, a metaloxycarbide film, and a metal oxynitride film.
 24. The patterning processaccording to claim 23, wherein the metal that constitutes the body to beprocessed is silicon, titanium, tungsten, hafnium, zirconium, chromium,germanium, copper, aluminum, iron, or an alloy of these metals.